diff --git a/admin/tool/mobile/classes/api.php b/admin/tool/mobile/classes/api.php
index b78de8f3147..c449ae69bf6 100644
--- a/admin/tool/mobile/classes/api.php
+++ b/admin/tool/mobile/classes/api.php
@@ -185,7 +185,7 @@ class api {
             $settings->frontpageloggedin = $CFG->frontpageloggedin;
             $settings->maxcategorydepth = $CFG->maxcategorydepth;
             $settings->frontpagecourselimit = $CFG->frontpagecourselimit;
-            $settings->numsections = course_get_format($SITE)->get_course()->numsections;
+            $settings->numsections = course_get_format($SITE)->get_last_section_number();
             $settings->newsitems = $SITE->newsitems;
             $settings->commentsperpage = $CFG->commentsperpage;
 
diff --git a/admin/tool/mobile/tests/externallib_test.php b/admin/tool/mobile/tests/externallib_test.php
index 6cf0f49a141..be10099c031 100644
--- a/admin/tool/mobile/tests/externallib_test.php
+++ b/admin/tool/mobile/tests/externallib_test.php
@@ -140,7 +140,7 @@ class tool_mobile_external_testcase extends externallib_advanced_testcase {
             array('name' => 'frontpageloggedin', 'value' => $CFG->frontpageloggedin),
             array('name' => 'maxcategorydepth', 'value' => $CFG->maxcategorydepth),
             array('name' => 'frontpagecourselimit', 'value' => $CFG->frontpagecourselimit),
-            array('name' => 'numsections', 'value' => course_get_format($SITE)->get_course()->numsections),
+            array('name' => 'numsections', 'value' => course_get_format($SITE)->get_last_section_number()),
             array('name' => 'newsitems', 'value' => $SITE->newsitems),
             array('name' => 'commentsperpage', 'value' => $CFG->commentsperpage),
             array('name' => 'disableuserimages', 'value' => $CFG->disableuserimages),
diff --git a/admin/tool/recyclebin/tests/events_test.php b/admin/tool/recyclebin/tests/events_test.php
index 05d519b8544..80ab6aa4352 100644
--- a/admin/tool/recyclebin/tests/events_test.php
+++ b/admin/tool/recyclebin/tests/events_test.php
@@ -121,7 +121,7 @@ class tool_recyclebin_events_testcase extends advanced_testcase {
         $sink = $this->redirectEvents();
         $rb->restore_item($item);
         $events = $sink->get_events();
-        $event = $events[6];
+        $event = $events[count($events) - 2];
 
         // Check that the event contains the expected values.
         $this->assertInstanceOf('\tooL_recyclebin\event\category_bin_item_restored', $event);
diff --git a/blocks/section_links/block_section_links.php b/blocks/section_links/block_section_links.php
index cc7c88c46a4..7f126833069 100644
--- a/blocks/section_links/block_section_links.php
+++ b/blocks/section_links/block_section_links.php
@@ -81,35 +81,26 @@ class block_section_links extends block_base {
 
         $course = $this->page->course;
         $courseformat = course_get_format($course);
-        $courseformatoptions = $courseformat->get_format_options();
+        $numsections = $courseformat->get_last_section_number();
         $context = context_course::instance($course->id);
 
         // Course format options 'numsections' is required to display the block.
-        if (empty($courseformatoptions['numsections'])) {
+        if (empty($numsections)) {
             return $this->content;
         }
 
-        // Prepare the highlight value.
-        if ($course->format == 'weeks') {
-            $highlight = ceil((time() - $course->startdate) / 604800);
-        } else if ($course->format == 'topics') {
-            $highlight = $course->marker;
-        } else {
-            $highlight = 0;
-        }
-
         // Prepare the increment value.
-        if (!empty($config->numsections1) and ($courseformatoptions['numsections'] > $config->numsections1)) {
+        if (!empty($config->numsections1) and ($numsections > $config->numsections1)) {
             $inc = $config->incby1;
-        } else if ($courseformatoptions['numsections'] > 22) {
+        } else if ($numsections > 22) {
             $inc = 2;
         } else {
             $inc = 1;
         }
-        if (!empty($config->numsections2) and ($courseformatoptions['numsections'] > $config->numsections2)) {
+        if (!empty($config->numsections2) and ($numsections > $config->numsections2)) {
             $inc = $config->incby2;
         } else {
-            if ($courseformatoptions['numsections'] > 40) {
+            if ($numsections > 40) {
                 $inc = 5;
             }
         }
@@ -119,8 +110,9 @@ class block_section_links extends block_base {
         $canviewhidden = has_capability('moodle/course:update', $context);
         $coursesections = $courseformat->get_sections();
         $coursesectionscount = count($coursesections);
+        $sectiontojumpto = false;
         for ($i = $inc; $i <= $coursesectionscount; $i += $inc) {
-            if ($i > $courseformatoptions['numsections'] || !isset($coursesections[$i])) {
+            if ($i > $numsections || !isset($coursesections[$i])) {
                 continue;
             }
             $section = $coursesections[$i];
@@ -128,16 +120,16 @@ class block_section_links extends block_base {
                 $sections[$i] = (object)array(
                     'section' => $section->section,
                     'visible' => $section->visible,
-                    'highlight' => ($section->section == $highlight)
+                    'highlight' => false
                 );
+                if ($courseformat->is_section_current($section)) {
+                    $sections[$i]->highlight = true;
+                    $sectiontojumpto = $section->section;
+                }
             }
         }
 
         if (!empty($sections)) {
-            $sectiontojumpto = false;
-            if ($highlight && isset($sections[$highlight]) && ($sections[$highlight]->visible || $canviewhidden)) {
-                $sectiontojumpto = $highlight;
-            }
             // Render the sections.
             $renderer = $this->page->get_renderer('block_section_links');
             $this->content->text = $renderer->render_section_links($this->page->course, $sections, $sectiontojumpto);
diff --git a/blocks/section_links/tests/behat/block_section_links_course.feature b/blocks/section_links/tests/behat/block_section_links_course.feature
index f43f6fd9287..d37e5608051 100644
--- a/blocks/section_links/tests/behat/block_section_links_course.feature
+++ b/blocks/section_links/tests/behat/block_section_links_course.feature
@@ -6,8 +6,8 @@ Feature: The section links block allows users to quickly navigate around a moodl
 
   Background:
     Given the following "courses" exist:
-      | fullname | shortname | category |
-      | Course 1 | C1        | 0        |
+      | fullname | shortname | category | numsections | coursedisplay |
+      | Course 1 | C1        | 0        | 20          | 1             |
     And the following "users" exist:
       | username | firstname | lastname | email |
       | teacher1 | Teacher   | 1        | teacher1@example.com |
@@ -21,11 +21,6 @@ Feature: The section links block allows users to quickly navigate around a moodl
       | Assignment name | Test assignment 1 |
       | Description | Offline text |
       | assignsubmission_file_enabled | 0 |
-    And I navigate to "Edit settings" node in "Course administration"
-    And I set the following fields to these values:
-      | id_numsections   | 20 |
-      | id_coursedisplay | Show one section per page |
-    And I press "Save and display"
 
   Scenario: Add the section links block to a course.
     Given I add the "Section links" block
diff --git a/course/changenumsections.php b/course/changenumsections.php
index 584691f1b40..a7b9495b76b 100644
--- a/course/changenumsections.php
+++ b/course/changenumsections.php
@@ -29,7 +29,11 @@ require_once(__DIR__.'/../config.php');
 require_once($CFG->dirroot.'/course/lib.php');
 
 $courseid = required_param('courseid', PARAM_INT);
-$increase = optional_param('increase', true, PARAM_BOOL);
+$increase = optional_param('increase', null, PARAM_BOOL);
+$insertsection = optional_param('insertsection', null, PARAM_INT); // Insert section at position; 0 means at the end.
+$returnurl = optional_param('returnurl', null, PARAM_LOCALURL);    // Where to return to after the action.
+$sectionreturn = optional_param('sectionreturn', null, PARAM_INT); // Section to return to, ignored if $returnurl is specified.
+
 $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
 $courseformatoptions = course_get_format($course)->get_format_options();
 
@@ -40,10 +44,11 @@ require_login($course);
 require_capability('moodle/course:update', context_course::instance($course->id));
 require_sesskey();
 
-if (isset($courseformatoptions['numsections'])) {
+if (isset($courseformatoptions['numsections']) && $increase !== null) {
     if ($increase) {
         // Add an additional section.
         $courseformatoptions['numsections']++;
+        course_create_sections_if_missing($course, $courseformatoptions['numsections']);
     } else {
         // Remove a section.
         $courseformatoptions['numsections']--;
@@ -55,9 +60,22 @@ if (isset($courseformatoptions['numsections'])) {
         update_course((object)array('id' => $course->id,
             'numsections' => $courseformatoptions['numsections']));
     }
+    if (!$returnurl) {
+        $returnurl = course_get_url($course);
+        $returnurl->set_anchor('changenumsections');
+    }
+
+} else if (course_get_format($course)->uses_sections() && $insertsection !== null) {
+    if ($insertsection) {
+        // Inserting sections at any position except in the very end requires capability to move sections.
+        require_capability('moodle/course:movesections', context_course::instance($course->id));
+    }
+    $section = course_create_section($course, $insertsection);
+    if (!$returnurl) {
+        $returnurl = course_get_url($course, $section->section,
+            ($sectionreturn !== null) ? ['sr' => $sectionreturn] : []);
+    }
 }
 
-$url = course_get_url($course);
-$url->set_anchor('changenumsections');
 // Redirect to where we were..
-redirect($url);
+redirect($returnurl);
diff --git a/course/externallib.php b/course/externallib.php
index 73370acc2db..b2ccd3ffa2e 100644
--- a/course/externallib.php
+++ b/course/externallib.php
@@ -160,7 +160,7 @@ class core_course_external extends external_api {
             //retrieve sections
             $modinfo = get_fast_modinfo($course);
             $sections = $modinfo->get_section_info_all();
-            $coursenumsections = course_get_format($course)->get_course()->numsections;
+            $coursenumsections = course_get_format($course)->get_last_section_number();
 
             //for each sections (first displayed to last displayed)
             $modinfosections = $modinfo->get_sections();
@@ -468,6 +468,8 @@ class core_course_external extends external_api {
                     // For backward-compartibility
                     $courseinfo['hiddensections'] = $courseformatoptions['hiddensections'];
                 }
+                // Return numsections for backward-compatibility with clients who expect it.
+                $courseinfo['numsections'] = course_get_format($course)->get_last_section_number();
                 $courseinfo['groupmode'] = $course->groupmode;
                 $courseinfo['groupmodeforce'] = $course->groupmodeforce;
                 $courseinfo['defaultgroupingid'] = $course->defaultgroupingid;
diff --git a/course/format/lib.php b/course/format/lib.php
index 0c7a4f265af..17f28514442 100644
--- a/course/format/lib.php
+++ b/course/format/lib.php
@@ -265,6 +265,28 @@ abstract class format_base {
         return $this->course;
     }
 
+    /**
+     * Method used in the rendered and during backup instead of legacy 'numsections'
+     *
+     * Default renderer will treat sections with sectionnumber greater that the value returned by this
+     * method as "orphaned" and not display them on the course page unless in editing mode.
+     * Backup will store this value as 'numsections'.
+     *
+     * This method ensures that 3rd party course format plugins that still use 'numsections' continue to
+     * work but at the same time we no longer expect formats to have 'numsections' property.
+     *
+     * @return int
+     */
+    public function get_last_section_number() {
+        $course = $this->get_course();
+        if (isset($course->numsections)) {
+            return $course->numsections;
+        }
+        $modinfo = get_fast_modinfo($course);
+        $sections = $modinfo->get_section_info_all();
+        return (int)max(array_keys($sections));
+    }
+
     /**
      * Returns true if the course has a front page.
      *
diff --git a/course/format/renderer.php b/course/format/renderer.php
index da25b20b067..eeb126f1016 100644
--- a/course/format/renderer.php
+++ b/course/format/renderer.php
@@ -303,7 +303,8 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
         $sectionreturn = $onsectionpage ? $section->section : null;
 
         $coursecontext = context_course::instance($course->id);
-        $isstealth = isset($course->numsections) && ($section->section > $course->numsections);
+        $numsections = course_get_format($course)->get_last_section_number();
+        $isstealth = $section->section > $numsections;
 
         $baseurl = course_get_url($course, $sectionreturn);
         $baseurl->param('sesskey', sesskey());
@@ -369,7 +370,7 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
                         }
 
                         $url = clone($baseurl);
-                        if ($section->section < $course->numsections) { // Add a arrow to move section down.
+                        if ($section->section < $numsections) { // Add a arrow to move section down.
                             $url->param('section', $section->section);
                             $url->param('move', 1);
                             $strmovedown = get_string('movedown');
@@ -643,7 +644,8 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
         }
 
         $forward = $sectionno + 1;
-        while ($forward <= $course->numsections and empty($links['next'])) {
+        $numsections = course_get_format($course)->get_last_section_number();
+        while ($forward <= $numsections and empty($links['next'])) {
             if ($canviewhidden || $sections[$forward]->uservisible) {
                 $params = array();
                 if (!$sections[$forward]->visible) {
@@ -731,7 +733,8 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
         $sectionmenu[course_get_url($course)->out(false)] = get_string('maincoursepage');
         $modinfo = get_fast_modinfo($course);
         $section = 1;
-        while ($section <= $course->numsections) {
+        $numsections = course_get_format($course)->get_last_section_number();
+        while ($section <= $numsections) {
             $thissection = $modinfo->get_section_info($section);
             $showsection = $thissection->uservisible or !$course->hiddensections;
             if (($showsection) && ($section != $displaysection) && ($url = course_get_url($course, $section))) {
@@ -869,6 +872,7 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
 
         // Now the list of sections..
         echo $this->start_section_list();
+        $numsections = course_get_format($course)->get_last_section_number();
 
         foreach ($modinfo->get_section_info_all() as $section => $thissection) {
             if ($section == 0) {
@@ -881,7 +885,7 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
                 }
                 continue;
             }
-            if ($section > $course->numsections) {
+            if ($section > $numsections) {
                 // activities inside this section are 'orphaned', this section will be printed as 'stealth' below
                 continue;
             }
@@ -917,7 +921,7 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
         if ($PAGE->user_is_editing() and has_capability('moodle/course:update', $context)) {
             // Print stealth sections if present.
             foreach ($modinfo->get_section_info_all() as $section => $thissection) {
-                if ($section <= $course->numsections or empty($modinfo->sections[$section])) {
+                if ($section <= $numsections or empty($modinfo->sections[$section])) {
                     // this is not stealth section or it is empty
                     continue;
                 }
@@ -928,6 +932,34 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
 
             echo $this->end_section_list();
 
+            echo $this->change_number_sections($course, 0);
+        } else {
+            echo $this->end_section_list();
+        }
+
+    }
+
+    /**
+     * Returns controls in the bottom of the page to increase/decrease number of sections
+     *
+     * @param stdClass $course
+     * @param int|null $sectionreturn
+     * @return string
+     */
+    protected function change_number_sections($course, $sectionreturn = null) {
+        $coursecontext = context_course::instance($course->id);
+        if (!has_capability('moodle/course:update', $coursecontext)) {
+            return '';
+        }
+
+        $options = course_get_format($course)->get_format_options();
+        $supportsnumsections = array_key_exists('numsections', $options);
+
+        if ($supportsnumsections) {
+            // Current course format has 'numsections' option, which is very confusing and we suggest course format
+            // developers to get rid of it (see MDL-57769 on how to do it).
+            // Display "Increase section" / "Decrease section" links.
+
             echo html_writer::start_tag('div', array('id' => 'changenumsections', 'class' => 'mdl-right'));
 
             // Increase number of sections.
@@ -951,10 +983,28 @@ abstract class format_section_renderer_base extends plugin_renderer_base {
             }
 
             echo html_writer::end_tag('div');
-        } else {
-            echo $this->end_section_list();
-        }
 
+        } else if (course_get_format($course)->uses_sections()) {
+            // Current course format does not have 'numsections' option but it has multiple sections suppport.
+            // Display the "Add section" link that will insert a section in the end.
+            // Note to course format developers: inserting sections in the other positions should check both
+            // capabilities 'moodle/course:update' and 'moodle/course:movesections'.
+
+            echo html_writer::start_tag('div', array('id' => 'changenumsections', 'class' => 'mdl-right'));
+            if (get_string_manager()->string_exists('addsection', 'format_'.$course->format)) {
+                $straddsection = get_string('addsection', 'format_'.$course->format);
+            } else {
+                $straddsection = get_string('addsection');
+            }
+            $url = new moodle_url('/course/changenumsections.php',
+                ['courseid' => $course->id, 'insertsection' => 0, 'sesskey' => sesskey()]);
+            if ($sectionreturn !== null) {
+                $url->param('sectionreturn', $sectionreturn);
+            }
+            $icon = $this->output->pix_icon('t/add', $straddsection);
+            echo html_writer::link($url, $icon . $straddsection, array('class' => 'add-section'));
+            echo html_writer::end_tag('div');
+        }
     }
 
     /**
diff --git a/course/format/upgrade.txt b/course/format/upgrade.txt
index f5cf7caf072..5beb8964827 100644
--- a/course/format/upgrade.txt
+++ b/course/format/upgrade.txt
@@ -10,6 +10,11 @@ Overview of this plugin type at http://docs.moodle.org/dev/Course_formats
   must check $cm->is_visible_on_course_page() when displaying activities list on the course page instead of $cm->uservisible.
   For all other plugins except course formats the same property $cm->uservisible indicates if the activity contents
   is actually available to student.
+* Option "Number of sections" (numsections) was removed from topics and weeks formats, instead the actual number of records
+  in the course_sections table is treated as a number of sections (excluding section 0 that should always be present).
+* Method create_course() will populate the new course with empty sections if $data->numsections is provided even if
+  "numsections" is not an option defined by the course format.
+* course/changenumsections.php can now be used to insert sections at any positions
 
 === 3.2 ===
 * Callback delete_course is deprecated and should be replaced with observer for event \core\event\course_content_deleted
diff --git a/course/format/weeks/lang/en/format_weeks.php b/course/format/weeks/lang/en/format_weeks.php
index 61626e0454d..5fc3a4be3cd 100644
--- a/course/format/weeks/lang/en/format_weeks.php
+++ b/course/format/weeks/lang/en/format_weeks.php
@@ -23,6 +23,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+$string['addsection'] = 'Add week';
 $string['currentsection'] = 'This week';
 $string['editsection'] = 'Edit week';
 $string['editsectionname'] = 'Edit week name';
diff --git a/course/lib.php b/course/lib.php
index 980173f8307..20a1718d47c 100644
--- a/course/lib.php
+++ b/course/lib.php
@@ -832,6 +832,52 @@ function add_course_module($mod) {
     return $cmid;
 }
 
+/**
+ * Creates a course section and adds it to the specified position
+ *
+ * @param int|stdClass $courseorid course id or course object
+ * @param int $position position to add to, 0 means to the end. If position is greater than
+ *        number of existing secitons, the section is added to the end. This will become sectionnum of the
+ *        new section. All existing sections at this or bigger position will be shifted down.
+ * @param bool $skipcheck the check has already been made and we know that the section with this position does not exist
+ * @return stdClass created section object
+ */
+function course_create_section($courseorid, $position = 0, $skipcheck = false) {
+    global $DB;
+    $courseid = is_object($courseorid) ? $courseorid->id : $courseorid;
+
+    // Find the last sectionnum among existing sections.
+    if ($skipcheck) {
+        $lastsection = $position - 1;
+    } else {
+        $lastsection = (int)$DB->get_field_sql('SELECT max(section) from {course_sections} WHERE course = ?', [$courseid]);
+    }
+
+    // First add section to the end.
+    $cw = new stdClass();
+    $cw->course   = $courseid;
+    $cw->section  = $lastsection + 1;
+    $cw->summary  = '';
+    $cw->summaryformat = FORMAT_HTML;
+    $cw->sequence = '';
+    $cw->name = null;
+    $cw->visible = 1;
+    $cw->availability = null;
+    $cw->id = $DB->insert_record("course_sections", $cw);
+
+    // Now move it to the specified position.
+    if ($position > 0 && $position <= $lastsection) {
+        $course = is_object($courseorid) ? $courseorid : get_course($courseorid);
+        move_section_to($course, $cw->section, $position, true);
+        $cw->section = $position;
+    }
+
+    core\event\course_section_created::create_from_section($cw)->trigger();
+
+    rebuild_course_cache($courseid, true);
+    return $cw;
+}
+
 /**
  * Creates missing course section(s) and rebuilds course cache
  *
@@ -840,31 +886,17 @@ function add_course_module($mod) {
  * @return bool if there were any sections created
  */
 function course_create_sections_if_missing($courseorid, $sections) {
-    global $DB;
     if (!is_array($sections)) {
         $sections = array($sections);
     }
     $existing = array_keys(get_fast_modinfo($courseorid)->get_section_info_all());
-    if (is_object($courseorid)) {
-        $courseorid = $courseorid->id;
-    }
-    $coursechanged = false;
-    foreach ($sections as $sectionnum) {
-        if (!in_array($sectionnum, $existing)) {
-            $cw = new stdClass();
-            $cw->course   = $courseorid;
-            $cw->section  = $sectionnum;
-            $cw->summary  = '';
-            $cw->summaryformat = FORMAT_HTML;
-            $cw->sequence = '';
-            $id = $DB->insert_record("course_sections", $cw);
-            $coursechanged = true;
+    if ($newsections = array_diff($sections, $existing)) {
+        foreach ($newsections as $sectionnum) {
+            course_create_section($courseorid, $sectionnum, true);
         }
+        return true;
     }
-    if ($coursechanged) {
-        rebuild_course_cache($courseorid, true);
-    }
-    return $coursechanged;
+    return false;
 }
 
 /**
@@ -2398,8 +2430,14 @@ function create_course($data, $editoroptions = NULL) {
     // Setup the blocks
     blocks_add_default_course_blocks($course);
 
-    // Create a default section.
-    course_create_sections_if_missing($course, 0);
+    // Create default section and initial sections if specified (unless they've already been created earlier).
+    // We do not want to call course_create_sections_if_missing() because to avoid creating course cache.
+    $numsections = isset($data->numsections) ? $data->numsections : 0;
+    $existingsections = $DB->get_fieldset_sql('SELECT section from {course_sections} WHERE course = ?', [$newcourseid]);
+    $newsections = array_diff(range(0, $numsections), $existingsections);
+    foreach ($newsections as $sectionnum) {
+        course_create_section($newcourseid, $sectionnum, true);
+    }
 
     // Save any custom role names.
     save_local_role_names($course->id, (array)$data);
diff --git a/course/tests/behat/activities_visibility_icons.feature b/course/tests/behat/activities_visibility_icons.feature
index a89880c5a3a..1af07b9e633 100644
--- a/course/tests/behat/activities_visibility_icons.feature
+++ b/course/tests/behat/activities_visibility_icons.feature
@@ -122,39 +122,6 @@ Feature: Toggle activities visibility from the course page
     And I should see "(There are no discussion topics yet in this forum)"
     And I log out
 
-  @javascript
-  Scenario: Activities can be shown and hidden inside an orphaned section
-    Given the following "users" exist:
-      | username | firstname | lastname | email |
-      | teacher1 | Teacher | 1 | teacher1@example.com |
-    And the following "courses" exist:
-      | fullname | shortname | format | numsections |
-      | Course 1 | C1 | topics | 2 |
-    And the following "course enrolments" exist:
-      | user | course | role |
-      | teacher1 | C1 | editingteacher |
-    And I log in as "teacher1"
-    And I follow "Course 1"
-    And I turn editing mode on
-    And I add a "Forum" to section "2" and I fill the form with:
-      | Forum name | Test forum name |
-      | Description | Test forum description |
-      | Visible | Show |
-    When I click on ".reduce-sections" "css_element"
-    Then "Test forum name" activity should be visible
-    And I open "Test forum name" actions menu
-    And "Test forum name" actions menu should not have "Show" item
-    And "Test forum name" actions menu should not have "Make available" item
-    And "Test forum name" actions menu should not have "Make unavailable" item
-    And I click on "Hide" "link" in the "Test forum name" activity
-    And "Test forum name" activity should be hidden
-    And I open "Test forum name" actions menu
-    And "Test forum name" actions menu should not have "Hide" item
-    And "Test forum name" actions menu should not have "Make available" item
-    And "Test forum name" actions menu should not have "Make unavailable" item
-    And I click on "Show" "link" in the "Test forum name" activity
-    And "Test forum name" activity should be visible
-
   @javascript
   Scenario: Activities can be made available but not visible on a course page
     Given the following "users" exist:
diff --git a/course/tests/courselib_test.php b/course/tests/courselib_test.php
index c726278b396..374aaafc64d 100644
--- a/course/tests/courselib_test.php
+++ b/course/tests/courselib_test.php
@@ -563,7 +563,6 @@ class core_course_courselib_testcase extends advanced_testcase {
         $course->summaryformat = FORMAT_PLAIN;
         $course->format = 'topics';
         $course->newsitems = 0;
-        $course->numsections = 5;
         $course->category = $defaultcategory;
         $original = (array) $course;
 
@@ -609,25 +608,26 @@ class core_course_courselib_testcase extends advanced_testcase {
         global $DB;
         $this->resetAfterTest(true);
 
+        $numsections = 5;
         $course = $this->getDataGenerator()->create_course(
                 array('shortname' => 'GrowingCourse',
                     'fullname' => 'Growing Course',
-                    'numsections' => 5),
+                    'numsections' => $numsections),
                 array('createsections' => true));
 
         // Ensure all 6 (0-5) sections were created and course content cache works properly
         $sectionscreated = array_keys(get_fast_modinfo($course)->get_section_info_all());
-        $this->assertEquals(range(0, $course->numsections), $sectionscreated);
+        $this->assertEquals(range(0, $numsections), $sectionscreated);
 
         // this will do nothing, section already exists
-        $this->assertFalse(course_create_sections_if_missing($course, $course->numsections));
+        $this->assertFalse(course_create_sections_if_missing($course, $numsections));
 
         // this will create new section
-        $this->assertTrue(course_create_sections_if_missing($course, $course->numsections + 1));
+        $this->assertTrue(course_create_sections_if_missing($course, $numsections + 1));
 
         // Ensure all 7 (0-6) sections were created and modinfo/sectioninfo cache works properly
         $sectionscreated = array_keys(get_fast_modinfo($course)->get_section_info_all());
-        $this->assertEquals(range(0, $course->numsections + 1), $sectionscreated);
+        $this->assertEquals(range(0, $numsections + 1), $sectionscreated);
     }
 
     public function test_update_course() {
@@ -957,31 +957,23 @@ class core_course_courselib_testcase extends advanced_testcase {
         // Delete last section.
         $this->assertTrue(course_delete_section($course, 6, true));
         $this->assertFalse($DB->record_exists('course_modules', array('id' => $assign6->cmid)));
-        $this->assertEquals(5, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(5, course_get_format($course)->get_last_section_number());
 
         // Delete empty section.
         $this->assertTrue(course_delete_section($course, 4, false));
-        $this->assertEquals(4, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(4, course_get_format($course)->get_last_section_number());
 
         // Delete section in the middle (2).
         $this->assertFalse(course_delete_section($course, 2, false));
         $this->assertTrue(course_delete_section($course, 2, true));
         $this->assertFalse($DB->record_exists('course_modules', array('id' => $assign21->cmid)));
         $this->assertFalse($DB->record_exists('course_modules', array('id' => $assign22->cmid)));
-        $this->assertEquals(3, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(3, course_get_format($course)->get_last_section_number());
         $this->assertEquals(array(0 => array($assign0->cmid),
             1 => array($assign1->cmid),
             2 => array($assign3->cmid),
             3 => array($assign5->cmid)), get_fast_modinfo($course)->sections);
 
-        // Make last section orphaned.
-        update_course((object)array('id' => $course->id, 'numsections' => 2));
-        $this->assertEquals(2, course_get_format($course)->get_course()->numsections);
-
-        // Remove orphaned section.
-        $this->assertTrue(course_delete_section($course, 3, true));
-        $this->assertEquals(2, course_get_format($course)->get_course()->numsections);
-
         // Remove marked section.
         course_set_marker($course->id, 1);
         $this->assertTrue(course_get_format($course)->is_section_current(1));
@@ -3549,7 +3541,7 @@ class core_course_courselib_testcase extends advanced_testcase {
 
         // Delete empty section. No difference from normal, synchronous behaviour.
         $this->assertTrue(course_delete_section($course, 4, false, true));
-        $this->assertEquals(3, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(3, course_get_format($course)->get_last_section_number());
 
         // Delete a module in section 2 (using async). Need to verify this doesn't generate two tasks when we delete
         // the section in the next step.
@@ -3577,7 +3569,7 @@ class core_course_courselib_testcase extends advanced_testcase {
         $this->assertEquals(3, $DB->count_records('course_modules', ['section' => $sectionid, 'deletioninprogress' => 1]));
 
         // Confirm the section has been deleted.
-        $this->assertEquals(2, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(2, course_get_format($course)->get_last_section_number());
 
         // Check event fired.
         $events = $sink->get_events();
@@ -3646,7 +3638,7 @@ class core_course_courselib_testcase extends advanced_testcase {
 
         // Delete empty section. No difference from normal, synchronous behaviour.
         $this->assertTrue(course_delete_section($course, 4, false, true));
-        $this->assertEquals(3, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(3, course_get_format($course)->get_last_section_number());
 
         // Delete section in the middle (2).
         $section = $DB->get_record('course_sections', ['course' => $course->id, 'section' => '2']); // For event comparison.
@@ -3667,7 +3659,7 @@ class core_course_courselib_testcase extends advanced_testcase {
         $this->assertEmpty($cmcount);
 
         // Confirm the section has been deleted.
-        $this->assertEquals(2, course_get_format($course)->get_course()->numsections);
+        $this->assertEquals(2, course_get_format($course)->get_last_section_number());
 
         // Confirm the course_section_deleted event has been generated.
         $events = $sink->get_events();
diff --git a/course/tests/externallib_test.php b/course/tests/externallib_test.php
index 9616ca2bf15..66950284178 100644
--- a/course/tests/externallib_test.php
+++ b/course/tests/externallib_test.php
@@ -445,7 +445,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
                 $this->assertEquals($courseinfo->newsitems, $course2['newsitems']);
                 $this->assertEquals($courseinfo->startdate, $course2['startdate']);
                 $this->assertEquals($courseinfo->enddate, $course2['enddate']);
-                $this->assertEquals($courseinfo->numsections, $course2['numsections']);
+                $this->assertEquals(course_get_format($createdcourse['id'])->get_last_section_number(), $course2['numsections']);
                 $this->assertEquals($courseinfo->maxbytes, $course2['maxbytes']);
                 $this->assertEquals($courseinfo->showreports, $course2['showreports']);
                 $this->assertEquals($courseinfo->visible, $course2['visible']);
@@ -480,7 +480,8 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
                 $this->assertEquals($courseinfo->category, $course3['categoryid']);
                 $this->assertEquals($courseinfo->format, $course3['format']);
                 $this->assertEquals($courseinfo->hiddensections, $course3options['hiddensections']);
-                $this->assertEquals($courseinfo->numsections, $course3options['numsections']);
+                $this->assertEquals(course_get_format($createdcourse['id'])->get_last_section_number(),
+                    $course3options['numsections']);
                 $this->assertEquals($courseinfo->coursedisplay, $course3options['coursedisplay']);
             } else {
                 throw moodle_exception('Unexpected shortname');
@@ -612,7 +613,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
             $this->assertEquals($course['newsitems'], $dbcourse->newsitems);
             $this->assertEquals($course['startdate'], $dbcourse->startdate);
             $this->assertEquals($course['enddate'], $dbcourse->enddate);
-            $this->assertEquals($course['numsections'], $dbcourse->numsections);
+            $this->assertEquals($course['numsections'], course_get_format($dbcourse)->get_last_section_number());
             $this->assertEquals($course['maxbytes'], $dbcourse->maxbytes);
             $this->assertEquals($course['showreports'], $dbcourse->showreports);
             $this->assertEquals($course['visible'], $dbcourse->visible);
@@ -626,7 +627,6 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
             $this->assertEquals($course['enablecompletion'], $dbcourse->enablecompletion);
             if ($dbcourse->format === 'topics') {
                 $this->assertEquals($course['courseformatoptions'], array(
-                    array('name' => 'numsections', 'value' => $dbcourse->numsections),
                     array('name' => 'hiddensections', 'value' => $dbcourse->hiddensections),
                     array('name' => 'coursedisplay', 'value' => $dbcourse->coursedisplay),
                 ));
@@ -744,7 +744,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
      */
     private function prepare_get_course_contents_test() {
         global $DB;
-        $course  = self::getDataGenerator()->create_course();
+        $course  = self::getDataGenerator()->create_course(['numsections' => 2]);
         $forumdescription = 'This is the forum description';
         $forum = $this->getDataGenerator()->create_module('forum',
             array('course' => $course->id, 'intro' => $forumdescription),
@@ -908,7 +908,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
         // We need to execute the return values cleaning process to simulate the web service server.
         $sections = external_api::clean_returnvalue(core_course_external::get_course_contents_returns(), $sections);
 
-        $this->assertCount(2, $sections);
+        $this->assertCount(3, $sections);
         $this->assertCount(1, $sections[0]['modules']);
         $this->assertEquals($forumcm->id, $sections[0]['modules'][0]["id"]);
     }
@@ -950,7 +950,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
         // We need to execute the return values cleaning process to simulate the web service server.
         $sections = external_api::clean_returnvalue(core_course_external::get_course_contents_returns(), $sections);
 
-        $this->assertCount(2, $sections);
+        $this->assertCount(3, $sections);
         $this->assertCount(1, $sections[0]['modules']);
         $this->assertEquals($forumcm->id, $sections[0]['modules'][0]["id"]);
     }
@@ -972,7 +972,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
         // We need to execute the return values cleaning process to simulate the web service server.
         $sections = external_api::clean_returnvalue(core_course_external::get_course_contents_returns(), $sections);
 
-        $this->assertCount(2, $sections);
+        $this->assertCount(3, $sections);
         $this->assertCount(1, $sections[0]['modules']);
         $this->assertEquals("page", $sections[0]['modules'][0]["modname"]);
         $this->assertEquals($pagecm->instance, $sections[0]['modules'][0]["instance"]);
@@ -1076,7 +1076,6 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
         $course2['newsitems'] = 3;
         $course2['startdate'] = 1420092000; // 01/01/2015.
         $course2['enddate'] = 1422669600; // 01/31/2015.
-        $course2['numsections'] = 4;
         $course2['maxbytes'] = 100000;
         $course2['showreports'] = 1;
         $course2['visible'] = 0;
@@ -1112,7 +1111,6 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
                 $this->assertEquals($course2['newsitems'], $courseinfo->newsitems);
                 $this->assertEquals($course2['startdate'], $courseinfo->startdate);
                 $this->assertEquals($course2['enddate'], $courseinfo->enddate);
-                $this->assertEquals($course2['numsections'], $courseinfo->numsections);
                 $this->assertEquals($course2['maxbytes'], $courseinfo->maxbytes);
                 $this->assertEquals($course2['showreports'], $courseinfo->showreports);
                 $this->assertEquals($course2['visible'], $courseinfo->visible);
@@ -1133,7 +1131,7 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
                 $this->assertEquals($course1['categoryid'], $courseinfo->category);
                 $this->assertEquals(FORMAT_MOODLE, $courseinfo->summaryformat);
                 $this->assertEquals('topics', $courseinfo->format);
-                $this->assertEquals(5, $courseinfo->numsections);
+                $this->assertEquals(5, course_get_format($course['id'])->get_last_section_number());
                 $this->assertEquals(0, $courseinfo->newsitems);
                 $this->assertEquals(FORMAT_MOODLE, $courseinfo->summaryformat);
             } else {
diff --git a/enrol/database/lib.php b/enrol/database/lib.php
index d25e14a91b6..b21578e5fc2 100644
--- a/enrol/database/lib.php
+++ b/enrol/database/lib.php
@@ -777,6 +777,9 @@ class enrol_database_plugin extends enrol_plugin {
             if ($templatecourse) {
                 if ($template = $DB->get_record('course', array('shortname'=>$templatecourse))) {
                     $template = fullclone(course_get_format($template)->get_course());
+                    if (!isset($template->numsections)) {
+                        $template->numsections = course_get_format($template)->get_last_section_number();
+                    }
                     unset($template->id);
                     unset($template->fullname);
                     unset($template->shortname);
diff --git a/enrol/database/tests/sync_test.php b/enrol/database/tests/sync_test.php
index 78298331577..03ea36f1e28 100644
--- a/enrol/database/tests/sync_test.php
+++ b/enrol/database/tests/sync_test.php
@@ -758,8 +758,7 @@ class enrol_database_testcase extends advanced_testcase {
         $course8['category'] = $defcat->id;
         $record = $DB->get_record('course', $course8);
         $this->assertFalse(empty($record));
-        $courseformatoptions = course_get_format($record)->get_format_options();
-        $this->assertEquals($courseformatoptions['numsections'], 666);
+        $this->assertEquals(666, course_get_format($record)->get_last_section_number());
 
         // Test invalid category.
 
diff --git a/lang/en/moodle.php b/lang/en/moodle.php
index 839580f0cce..85226c77162 100644
--- a/lang/en/moodle.php
+++ b/lang/en/moodle.php
@@ -71,6 +71,7 @@ $string['addresource'] = 'Add a resource...';
 $string['addresourceoractivity'] = 'Add an activity or resource';
 $string['addresourcetosection'] = 'Add a resource to section \'{$a}\'';
 $string['address'] = 'Address';
+$string['addsection'] = 'Add section';
 $string['addstudent'] = 'Add student';
 $string['addsubcategory'] = 'Add a subcategory';
 $string['addteacher'] = 'Add teacher';
@@ -740,6 +741,7 @@ $string['eventcourseresetended'] = 'Course reset ended';
 $string['eventcourseresetstarted'] = 'Course reset started';
 $string['eventcourserestored'] = 'Course restored';
 $string['eventcourseupdated'] = 'Course updated';
+$string['eventcoursesectioncreated'] = 'Course section created';
 $string['eventcoursesectiondeleted'] = 'Course section deleted';
 $string['eventcoursesectionupdated'] = 'Course section updated';
 $string['eventcoursemoduleinstancelistviewed'] = 'Course module instance list viewed';
diff --git a/lib/classes/event/course_section_created.php b/lib/classes/event/course_section_created.php
new file mode 100644
index 00000000000..9c1e789575d
--- /dev/null
+++ b/lib/classes/event/course_section_created.php
@@ -0,0 +1,131 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Course section created event.
+ *
+ * @package    core
+ * @copyright  2017 Marina Glancy
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core\event;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Course section created event class.
+ *
+ * @property-read array $other {
+ *      Extra information about event.
+ *
+ *      - int sectionnum: section number.
+ * }
+ *
+ * @package    core
+ * @copyright  2017 Marina Glancy
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class course_section_created extends base {
+
+    /**
+     * Init method.
+     *
+     * @return void
+     */
+    protected function init() {
+        $this->data['objecttable'] = 'course_sections';
+        $this->data['crud'] = 'c';
+        $this->data['edulevel'] = self::LEVEL_TEACHING;
+    }
+
+    /**
+     * Creates event from the section object
+     *
+     * @param \stdClass $section
+     * @return course_section_created
+     */
+    public static function create_from_section($section) {
+        $event = self::create([
+            'context' => \context_course::instance($section->course),
+            'objectid' => $section->id,
+            'other' => ['sectionnum' => $section->section]
+        ]);
+        $event->add_record_snapshot('course_sections', $section);
+        return $event;
+    }
+
+    /**
+     * Return localised event name.
+     *
+     * @return string
+     */
+    public static function get_name() {
+        return get_string('eventcoursesectioncreated');
+    }
+
+    /**
+     * Returns non-localised event description with id's for admin use only.
+     *
+     * @return string
+     */
+    public function get_description() {
+        return "The user with id '$this->userid' created section number '{$this->other['sectionnum']}' for the " .
+        "course with id '$this->courseid'";
+    }
+
+    /**
+     * Get URL related to the action.
+     *
+     * @return \moodle_url
+     */
+    public function get_url() {
+        return new \moodle_url('/course/editsection.php', array('id' => $this->objectid));
+    }
+
+    /**
+     * Custom validation.
+     *
+     * @throws \coding_exception
+     * @return void
+     */
+    protected function validate_data() {
+        parent::validate_data();
+
+        if (!isset($this->other['sectionnum'])) {
+            throw new \coding_exception('The \'sectionnum\' value must be set in other.');
+        }
+    }
+
+    /**
+     * Mapping for sections object during restore
+     *
+     * @return array
+     */
+    public static function get_objectid_mapping() {
+        return array('db' => 'course_sections', 'restore' => 'course_section');
+    }
+
+    /**
+     * Mapping for other fields during restore
+     *
+     * @return bool
+     */
+    public static function get_other_mapping() {
+        // Sectionnum does not need mapping because it's relative.
+        return false;
+    }
+}
diff --git a/lib/testing/generator/data_generator.php b/lib/testing/generator/data_generator.php
index 31f6ce16fbc..5b0bc694482 100644
--- a/lib/testing/generator/data_generator.php
+++ b/lib/testing/generator/data_generator.php
@@ -419,15 +419,14 @@ EOD;
             $record['tags'] = preg_split('/\s*,\s*/', trim($record['tags']), -1, PREG_SPLIT_NO_EMPTY);
         }
 
+        if (!empty($options['createsections']) && empty($record['numsections'])) {
+            // Since Moodle 3.3 function create_course() automatically creates sections if numsections is specified.
+            // For BC if 'createsections' is given but 'numsections' is not, assume the default value from config.
+            $record['numsections'] = get_config('moodlecourse', 'numsections');
+        }
+
         $course = create_course((object)$record);
         context_course::instance($course->id);
-        if (!empty($options['createsections'])) {
-            if (isset($course->numsections)) {
-                course_create_sections_if_missing($course, range(0, $course->numsections));
-            } else {
-                course_create_sections_if_missing($course, 0);
-            }
-        }
 
         return $course;
     }
diff --git a/lib/testing/tests/generator_test.php b/lib/testing/tests/generator_test.php
index ba6e012edc2..2d3e7e970f2 100644
--- a/lib/testing/tests/generator_test.php
+++ b/lib/testing/tests/generator_test.php
@@ -170,7 +170,7 @@ class core_test_generator_testcase extends advanced_testcase {
         $this->assertSame('', $course->idnumber);
         $this->assertSame('topics', $course->format);
         $this->assertEquals(0, $course->newsitems);
-        $this->assertEquals(5, $course->numsections);
+        $this->assertEquals(5, course_get_format($course)->get_last_section_number());
         $this->assertRegExp('/^Test course \d/', $course->summary);
         $this->assertSame(FORMAT_MOODLE, $course->summaryformat);