diff --git a/mod/data/classes/search/entry.php b/mod/data/classes/search/entry.php
index b1a6fd9fd61..b476cf8d45c 100644
--- a/mod/data/classes/search/entry.php
+++ b/mod/data/classes/search/entry.php
@@ -295,6 +295,10 @@ class entry extends \core_search\base_mod {
 
         foreach ($filteredcontents as $content) {
             $classname = $this->get_field_class_name($content->fieldtype);
+            if (!$classname) {
+                $content->addtemplateposition = -1;
+                continue;
+            }
             $content->priority = $classname::get_priority();
             $content->addtemplateposition = strpos($template, '[['.$content->fldname.']]');
         }
@@ -342,16 +346,22 @@ class entry extends \core_search\base_mod {
     }
 
     /**
-     * Returns the class name for that field type and includes it.
+     * Returns the class name for the given field type and includes it.
      *
      * @param string $fieldtype
-     * @return string
+     * @return string|null It will return the class name or null if the field type is not available.
      */
     protected function get_field_class_name($fieldtype) {
         global $CFG;
 
         $fieldtype = trim($fieldtype);
-        require_once($CFG->dirroot . '/mod/data/field/' . $fieldtype . '/field.class.php');
+
+        $fieldpath = $CFG->dirroot . '/mod/data/field/' . $fieldtype . '/field.class.php';
+        if (!file_exists($fieldpath)) {
+            return null;
+        }
+
+        require_once($fieldpath);
         return 'data_field_' . $fieldtype;
     }
 
diff --git a/mod/data/edit.php b/mod/data/edit.php
index 809a8435d95..26b3a697c73 100644
--- a/mod/data/edit.php
+++ b/mod/data/edit.php
@@ -258,25 +258,33 @@ if ($data->addtemplate){
     $replacements = array();
 
     ///then we generate strings to replace
-    foreach ($possiblefields as $eachfield){
+    foreach ($possiblefields as $eachfield) {
         $field = data_get_field($eachfield, $data);
-
         // To skip unnecessary calls to display_add_field().
-        if (strpos($data->addtemplate, "[[".$field->field->name."]]") !== false) {
-            // Replace the field tag.
-            $patterns[] = "[[".$field->field->name."]]";
+        if (strpos($data->addtemplate, "[[" . $field->field->name . "]]") !== false) {
+            // Display an error in case the field type is not found.
             $errors = '';
             if (!empty($fieldnotifications[$field->field->name])) {
                 foreach ($fieldnotifications[$field->field->name] as $notification) {
                     $errors .= $OUTPUT->notification($notification);
                 }
             }
-            $replacements[] = $errors . $field->display_add_field($rid, $datarecord);
-        }
-
-        // Replace the field id tag.
-        $patterns[] = "[[".$field->field->name."#id]]";
-        $replacements[] = 'field_'.$field->field->id;
+            // Replace the field tag.
+            $fielddisplay = '';
+            if ($field->type === 'unknown') {
+                if (has_capability('mod/data:manageentries', $context)) {
+                    // Display notification for users that can manage entries.
+                    $errors .= $OUTPUT->notification(get_string('missingfieldtype', 'data',
+                    (object)['name' => $field->field->name]));
+                }
+            } else {
+                $fielddisplay = $field->display_add_field($rid, $datarecord);
+            }
+            $patterns[] = "[[" . $field->field->name . "]]";
+            $replacements[] = $errors . $fielddisplay;
+        }    // Replace the field id tag.
+        $patterns[] = "[[" . $field->field->name . "#id]]";
+        $replacements[] = 'field_' . $field->field->id;
     }
 
     if (core_tag_tag::is_enabled('mod_data', 'data_records')) {
diff --git a/mod/data/field.php b/mod/data/field.php
index eb173872ad1..efc4e2d5280 100644
--- a/mod/data/field.php
+++ b/mod/data/field.php
@@ -268,9 +268,15 @@ switch ($mode) {
                 // Print confirmation message.
                 $field = data_get_field_from_id($fid, $data);
 
-                echo $OUTPUT->confirm('<strong>'.$field->name().': '.$field->field->name.'</strong><br /><br />'. get_string('confirmdeletefield','data'),
-                             'field.php?d='.$data->id.'&mode=delete&fid='.$fid.'&confirm=1',
-                             'field.php?d='.$data->id);
+                if ($field->type === 'unknown') {
+                    $fieldtypename = get_string('unknown', 'data');
+                } else {
+                    $fieldtypename = $field->name();
+                }
+                echo $OUTPUT->confirm('<strong>'.$fieldtypename.': '.$field->field->name.'</strong><br /><br />'.
+                            get_string('confirmdeletefield', 'data'),
+                            'field.php?d='.$data->id.'&mode=delete&fid='.$fid.'&confirm=1',
+                            'field.php?d='.$data->id);
 
                 echo $OUTPUT->footer();
                 exit;
@@ -336,6 +342,9 @@ $plugins = core_component::get_plugin_list('datafield');
 $menufield = array();
 
 foreach ($plugins as $plugin=>$fulldir){
+    if (!is_dir($fulldir)) {
+        continue;
+    }
     $menufield[$plugin] = get_string('pluginname', 'datafield_'.$plugin);    //get from language files
 }
 asort($menufield);    //sort in alphabetical order
@@ -379,6 +388,7 @@ if (($mode == 'new') && (!empty($newtype))) { // Adding a new field.
         $table->wrap = array(false,false,false,false);
 
         if ($fff = $DB->get_records('data_fields', array('dataid'=>$data->id),'id')){
+            $missingfieldtypes = [];
             foreach ($fff as $ff) {
 
                 $field = data_get_field($ff, $data);
@@ -397,15 +407,30 @@ if (($mode == 'new') && (!empty($newtype))) { // Adding a new field.
                     'mode'      => 'delete',
                 ));
 
-                $table->data[] = array(
-                    html_writer::link($displayurl, $field->field->name),
-                    $field->image() . '&nbsp;' . $field->name(),
+                // It display a notification when the field type does not exist.
+                $deletelink = html_writer::link($deleteurl, $OUTPUT->pix_icon('t/delete', get_string('delete')));
+                $editlink = html_writer::link($displayurl, $OUTPUT->pix_icon('t/edit', get_string('edit')));
+                if ($field->type === 'unknown') {
+                    $missingfieldtypes[] = $field->field->name;
+                    $fieldnamedata = $field->field->name;
+                    $fieltypedata = $field->field->type;
+                    $fieldlinkdata = $deletelink;
+                } else {
+                    $fieldnamedata = html_writer::link($displayurl, $field->field->name);
+                    $fieltypedata = $field->image() . '&nbsp;' . $field->name();
+                    $fieldlinkdata = $editlink . '&nbsp;' . $deletelink;
+                }
+
+                $table->data[] = [
+                    $fieldnamedata,
+                    $fieltypedata,
                     $field->field->required ? get_string('yes') : get_string('no'),
                     shorten_text($field->field->description, 30),
-                    html_writer::link($displayurl, $OUTPUT->pix_icon('t/edit', get_string('edit'))) .
-                        '&nbsp;' .
-                        html_writer::link($deleteurl, $OUTPUT->pix_icon('t/delete', get_string('delete'))),
-                );
+                    $fieldlinkdata
+                ];
+            }
+            if (!empty($missingfieldtypes)) {
+                echo $OUTPUT->notification(get_string('missingfieldtypes', 'data') . html_writer::alist($missingfieldtypes));
             }
         }
         echo html_writer::table($table);
diff --git a/mod/data/lang/en/data.php b/mod/data/lang/en/data.php
index d5074ca9c87..8098ab7f2a7 100644
--- a/mod/data/lang/en/data.php
+++ b/mod/data/lang/en/data.php
@@ -231,6 +231,11 @@ $string['invalidfieldid'] = 'Field ID is incorrect';
 $string['invalidfieldname'] = 'Please choose another name for this field';
 $string['invalidfieldtype'] = 'Field type is incorrect';
 $string['invalidid'] = 'Incorrect data ID';
+$string['missingfieldtype'] = 'Field type for {$a->name} not found';
+$string['missingfieldtypes'] = 'The following fields do not have their corresponding field types installed and will not be included in the forms when adding or editing entries.
+ Their labels may still show on the form, so please update the "Add entry template" accordingly:';
+$string['missingfieldtypeimport'] = 'The following fields were not imported because their corresponding field types are not installed:';
+$string['unknown'] = 'Unknown field';
 $string['invalidpreset'] = '{$a} is not a preset.';
 $string['invalidrecord'] = 'Incorrect record';
 $string['invalidurl'] = 'The URL you just entered is not valid';
diff --git a/mod/data/lib.php b/mod/data/lib.php
index cf98e01e6d3..877310c31a7 100644
--- a/mod/data/lib.php
+++ b/mod/data/lib.php
@@ -334,6 +334,10 @@ class data_field_base {     // Base class for Database Field Types (see field/*/
         if (empty($this->field)) {   // No field has been defined yet, try and make one
             $this->define_default_field();
         }
+        // Throw an exception if field type doen't exist. Anyway user should never access to edit a field with an unknown fieldtype.
+        if ($this->type === 'unknown') {
+            throw new \moodle_exception(get_string('missingfieldtype', 'data', (object)['name' => $this->field->name]));
+        }
         echo $OUTPUT->box_start('generalbox boxaligncenter boxwidthwide');
 
         echo '<form id="editfield" action="'.$CFG->wwwroot.'/mod/data/field.php" method="post">'."\n";
@@ -351,7 +355,13 @@ class data_field_base {     // Base class for Database Field Types (see field/*/
 
         echo $OUTPUT->heading($this->name(), 3);
 
-        require_once($CFG->dirroot.'/mod/data/field/'.$this->type.'/mod.html');
+        $filepath = $CFG->dirroot.'/mod/data/field/'.$this->type.'/mod.html';
+
+        if (!file_exists($filepath)) {
+            throw new \moodle_exception(get_string('missingfieldtype', 'data', (object)['name' => $this->field->name]));
+        } else {
+            require_once($filepath);
+        }
 
         echo html_writer::start_div('mt-3');
         echo html_writer::tag('input', null, array('type' => 'submit', 'value' => $savebutton,
@@ -883,7 +893,12 @@ function data_get_field_from_id($fieldid, $data){
 function data_get_field_new($type, $data) {
     global $CFG;
 
-    require_once($CFG->dirroot.'/mod/data/field/'.$type.'/field.class.php');
+    $filepath = $CFG->dirroot.'/mod/data/field/'.$type.'/field.class.php';
+    // It should never access this method if the subfield class doesn't exist.
+    if (!file_exists($filepath)) {
+        throw new \moodle_exception('invalidfieldtype', 'data');
+    }
+    require_once($filepath);
     $newfield = 'data_field_'.$type;
     $newfield = new $newfield(0, $data);
     return $newfield;
@@ -895,20 +910,24 @@ function data_get_field_new($type, $data) {
  * input: $param $field - record from db
  *
  * @global object
- * @param object $field
- * @param object $data
- * @param object $cm
- * @return object
+ * @param stdClass $field the field record
+ * @param stdClass $data the data instance
+ * @param stdClass|null $cm optional course module data
+ * @return data_field_base the field object instance or data_field_base if unkown type
  */
 function data_get_field($field, $data, $cm=null) {
     global $CFG;
-
-    if ($field) {
-        require_once('field/'.$field->type.'/field.class.php');
-        $newfield = 'data_field_'.$field->type;
-        $newfield = new $newfield($field, $data, $cm);
-        return $newfield;
+    if (!isset($field->type)) {
+        return new data_field_base($field);
     }
+    $filepath = $CFG->dirroot.'/mod/data/field/'.$field->type.'/field.class.php';
+    if (!file_exists($filepath)) {
+        return new data_field_base($field);
+    }
+    require_once($filepath);
+    $newfield = 'data_field_'.$field->type;
+    $newfield = new $newfield($field, $data, $cm);
+    return $newfield;
 }
 
 
@@ -1924,6 +1943,9 @@ function data_print_preference_form($data, $perpage, $search, $sort='', $order='
         $fieldname = preg_quote($fieldname, '/');
         $patterns[] = "/\[\[$fieldname\]\]/i";
         $searchfield = data_get_field_from_id($field->field->id, $data);
+        if ($searchfield->type === 'unknown') {
+            continue;
+        }
         if (!empty($search_array[$field->field->id]->data)) {
             $replacement[] = $searchfield->display_search_field($search_array[$field->field->id]->data);
         } else {
@@ -2622,7 +2644,7 @@ abstract class data_preset_importer {
      * @return bool
      */
     function import($overwritesettings) {
-        global $DB, $CFG;
+        global $DB, $CFG, $OUTPUT;
 
         $params = $this->get_preset_settings();
         $settings = $params->settings;
@@ -2643,7 +2665,7 @@ abstract class data_preset_importer {
                 }
                 else $preservedfields[$cid] = true;
             }
-
+            $missingfieldtypes = [];
             foreach ($newfields as $nid => $newfield) {
                 $cid = optional_param("field_$nid", -1, PARAM_INT);
 
@@ -2660,7 +2682,12 @@ abstract class data_preset_importer {
                     unset($fieldobject);
                 } else {
                     /* Make a new field */
-                    include_once("field/$newfield->type/field.class.php");
+                    $filepath = "field/$newfield->type/field.class.php";
+                    if (!file_exists($filepath)) {
+                        $missingfieldtypes[] = $newfield->name;
+                        continue;
+                    }
+                    include_once($filepath);
 
                     if (!isset($newfield->description)) {
                         $newfield->description = '';
@@ -2671,6 +2698,9 @@ abstract class data_preset_importer {
                     unset($fieldclass);
                 }
             }
+            if (!empty($missingfieldtypes)) {
+                echo $OUTPUT->notification(get_string('missingfieldtypeimport', 'data') . html_writer::alist($missingfieldtypes));
+            }
         }
 
         /* Get rid of all old unused data */
@@ -3108,7 +3138,12 @@ function data_import_csv($cm, $data, &$csvdata, $encoding, $fielddelimiter) {
                     unset($fieldnames[$id]); // To ensure the user provided content fields remain in the array once flipped.
                 } else {
                     $field = $rawfields[$name];
-                    require_once("$CFG->dirroot/mod/data/field/$field->type/field.class.php");
+                    $filepath = "$CFG->dirroot/mod/data/field/$field->type/field.class.php";
+                    if (!file_exists($filepath)) {
+                        $errorfield .= "'$name' ";
+                        continue;
+                    }
+                    require_once($filepath);
                     $classname = 'data_field_' . $field->type;
                     $fields[$name] = new $classname($field, $data, $cm);
                 }
diff --git a/mod/data/locallib.php b/mod/data/locallib.php
index 6a9b6111db3..0b52a9fb5c8 100644
--- a/mod/data/locallib.php
+++ b/mod/data/locallib.php
@@ -270,7 +270,11 @@ class data_portfolio_caller extends portfolio_module_caller_base {
             return true; // too early yet
         }
         foreach ($this->fieldtypes as $key => $field) {
-            require_once($CFG->dirroot . '/mod/data/field/' . $field .'/field.class.php');
+            $filepath = $CFG->dirroot . '/mod/data/field/' . $field .'/field.class.php';
+            if (!file_exists($filepath)) {
+                continue;
+            }
+            require_once($filepath);
             $this->fields[$key] = unserialize(serialize($this->fields[$key]));
         }
     }
@@ -970,7 +974,11 @@ function data_get_tag_title_field($dataid) {
         if ($field->addtemplateposition === false) {
             continue;
         }
-        require_once($CFG->dirroot . '/mod/data/field/' . $field->type . '/field.class.php');
+        $filepath = $CFG->dirroot . '/mod/data/field/' . $field->type . '/field.class.php';
+        if (!file_exists($filepath)) {
+            continue;
+        }
+        require_once($filepath);
         $classname = 'data_field_' . $field->type;
         $field->priority = $classname::get_priority();
         $filteredfields[] = $field;
@@ -1001,11 +1009,18 @@ function data_get_tag_title_field($dataid) {
  *
  * @param stdClass $field The field from the 'data_fields' table
  * @param stdClass $entry The entry from the 'data_records' table
- * @return string The title of the entry
+ * @return string|null It will return the title of the entry or null if the field type is not available.
  */
 function data_get_tag_title_for_entry($field, $entry) {
     global $CFG, $DB;
-    require_once($CFG->dirroot . '/mod/data/field/' . $field->type . '/field.class.php');
+    if (!isset($field->type)) {
+        return null;
+    }
+    $filepath = $CFG->dirroot . '/mod/data/field/' . $field->type . '/field.class.php';
+    if (!file_exists($filepath)) {
+        return null;
+    }
+    require_once($filepath);
 
     $classname = 'data_field_' . $field->type;
     $sql = "SELECT dc.*
@@ -1335,7 +1350,7 @@ function data_build_search_array($data, $paging, $searcharray, $defaults = null,
             $searchfield = data_get_field_from_id($field->id, $data);
             // Get field data to build search sql with.  If paging is false, get from user.
             // If paging is true, get data from $searcharray which is obtained from the $SESSION (see line 116).
-            if (!$paging) {
+            if (!$paging && $searchfield->type != 'unknown') {
                 $val = $searchfield->parse_search_field($defaults);
             } else {
                 // Set value from session if there is a value @ the required index.