diff --git a/backup/moodle2/restore_stepslib.php b/backup/moodle2/restore_stepslib.php
index b3d5322f70d..149f606ce46 100644
--- a/backup/moodle2/restore_stepslib.php
+++ b/backup/moodle2/restore_stepslib.php
@@ -485,6 +485,9 @@ class restore_gradebook_structure_step extends restore_structure_step {
         // Freeze gradebook calculations if needed.
         $this->gradebook_calculation_freeze();
 
+        // Ensure the module cache is current when recalculating grades.
+        rebuild_course_cache($this->get_courseid(), true);
+
         // Restore marks items as needing update. Update everything now.
         grade_regrade_final_grades($this->get_courseid());
     }
diff --git a/lib/grade/grade_item.php b/lib/grade/grade_item.php
index 60edaf60b92..769f69dfd3c 100644
--- a/lib/grade/grade_item.php
+++ b/lib/grade/grade_item.php
@@ -2495,8 +2495,22 @@ class grade_item extends grade_object {
      */
     public function get_context() {
         if ($this->itemtype == 'mod') {
-            $cm = get_fast_modinfo($this->courseid)->instances[$this->itemmodule][$this->iteminstance];
-            $context = \context_module::instance($cm->id);
+            $modinfo = get_fast_modinfo($this->courseid);
+            // Sometimes the course module cache is out of date and needs to be rebuilt.
+            if (!isset($modinfo->instances[$this->itemmodule][$this->iteminstance])) {
+                rebuild_course_cache($this->courseid, true);
+                $modinfo = get_fast_modinfo($this->courseid);
+            }
+            // Even with a rebuilt cache the module does not exist. This means the
+            // database is in an invalid state - we will log an error and return
+            // the course context but the calling code should be updated.
+            if (!isset($modinfo->instances[$this->itemmodule][$this->iteminstance])) {
+                mtrace(get_string('moduleinstancedoesnotexist', 'error'));
+                $context = \context_course::instance($this->courseid);
+            } else {
+                $cm = $modinfo->instances[$this->itemmodule][$this->iteminstance];
+                $context = \context_module::instance($cm->id);
+            }
         } else {
             $context = \context_course::instance($this->courseid);
         }
diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index d7663872446..0dab7f9f63f 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -813,6 +813,7 @@ class assign {
         }
 
         // Delete the instance.
+        // We must delete the module record after we delete the grade item.
         $DB->delete_records('assign', array('id'=>$this->get_instance()->id));
 
         return $result;
diff --git a/mod/assignment/lib.php b/mod/assignment/lib.php
index 9b125863bc7..40917e88372 100644
--- a/mod/assignment/lib.php
+++ b/mod/assignment/lib.php
@@ -71,12 +71,13 @@ function assignment_delete_instance($id){
         $result = false;
     }
 
+    grade_update('mod/assignment', $assignment->course, 'mod', 'assignment', $assignment->id, 0, NULL, array('deleted'=>1));
+
+    // We must delete the module record after we delete the grade item.
     if (! $DB->delete_records('assignment', array('id'=>$assignment->id))) {
         $result = false;
     }
 
-    grade_update('mod/assignment', $assignment->course, 'mod', 'assignment', $assignment->id, 0, NULL, array('deleted'=>1));
-
     return $result;
 }
 
diff --git a/mod/data/lib.php b/mod/data/lib.php
index 0fe8e85ac26..eace6e75fb8 100644
--- a/mod/data/lib.php
+++ b/mod/data/lib.php
@@ -1153,12 +1153,13 @@ function data_delete_instance($id) {    // takes the dataid
         $event->delete();
     }
 
-    // Delete the instance itself
-    $result = $DB->delete_records('data', array('id'=>$id));
-
     // cleanup gradebook
     data_grade_item_delete($data);
 
+    // Delete the instance itself
+    // We must delete the module record after we delete the grade item.
+    $result = $DB->delete_records('data', array('id'=>$id));
+
     return $result;
 }
 
diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index 830e051a4f9..80c06f28719 100644
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -305,12 +305,13 @@ function forum_delete_instance($id) {
 
     forum_tp_delete_read_records(-1, -1, -1, $forum->id);
 
+    forum_grade_item_delete($forum);
+
+    // We must delete the module record after we delete the grade item.
     if (!$DB->delete_records('forum', array('id'=>$forum->id))) {
         $result = false;
     }
 
-    forum_grade_item_delete($forum);
-
     return $result;
 }
 
diff --git a/mod/lesson/locallib.php b/mod/lesson/locallib.php
index 3bfd617341b..95850ccaa83 100644
--- a/mod/lesson/locallib.php
+++ b/mod/lesson/locallib.php
@@ -1642,6 +1642,9 @@ class lesson extends lesson_base {
 
         $this->delete_all_overrides();
 
+        grade_update('mod/lesson', $this->properties->course, 'mod', 'lesson', $this->properties->id, 0, null, array('deleted'=>1));
+
+        // We must delete the module record after we delete the grade item.
         $DB->delete_records("lesson", array("id"=>$this->properties->id));
         $DB->delete_records("lesson_pages", array("lessonid"=>$this->properties->id));
         $DB->delete_records("lesson_answers", array("lessonid"=>$this->properties->id));
@@ -1662,7 +1665,6 @@ class lesson extends lesson_base {
         $fs = get_file_storage();
         $fs->delete_area_files($context->id);
 
-        grade_update('mod/lesson', $this->properties->course, 'mod', 'lesson', $this->properties->id, 0, null, array('deleted'=>1));
         return true;
     }
 
diff --git a/mod/lti/lib.php b/mod/lti/lib.php
index 886519338f5..5becf387a9d 100644
--- a/mod/lti/lib.php
+++ b/mod/lti/lib.php
@@ -200,6 +200,7 @@ function lti_delete_instance($id) {
     $cm = get_coursemodule_from_instance('lti', $id);
     \core_completion\api::update_completion_date_event($cm->id, 'lti', $id, null);
 
+    // We must delete the module record after we delete the grade item.
     return $DB->delete_records("lti", array("id" => $basiclti->id));
 }
 
diff --git a/mod/quiz/lib.php b/mod/quiz/lib.php
index 6dd7d885db4..e04459ee9d7 100644
--- a/mod/quiz/lib.php
+++ b/mod/quiz/lib.php
@@ -203,6 +203,7 @@ function quiz_delete_instance($id) {
     }
 
     quiz_grade_item_delete($quiz);
+    // We must delete the module record after we delete the grade item.
     $DB->delete_records('quiz', array('id' => $quiz->id));
 
     return true;
diff --git a/mod/scorm/lib.php b/mod/scorm/lib.php
index 234a33e7871..ae9672e885e 100644
--- a/mod/scorm/lib.php
+++ b/mod/scorm/lib.php
@@ -301,6 +301,10 @@ function scorm_delete_instance($id) {
         }
         $DB->delete_records('scorm_scoes', array('scorm' => $scorm->id));
     }
+
+    scorm_grade_item_delete($scorm);
+
+    // We must delete the module record after we delete the grade item.
     if (! $DB->delete_records('scorm', array('id' => $scorm->id))) {
         $result = false;
     }
@@ -327,8 +331,6 @@ function scorm_delete_instance($id) {
         $result = false;
     }*/
 
-    scorm_grade_item_delete($scorm);
-
     return $result;
 }
 
diff --git a/mod/workshop/lib.php b/mod/workshop/lib.php
index 8cdf52b3c05..73d05e2e40e 100644
--- a/mod/workshop/lib.php
+++ b/mod/workshop/lib.php
@@ -290,13 +290,14 @@ function workshop_delete_instance($id) {
         $event->delete();
     }
 
-    // finally remove the workshop record itself
-    $DB->delete_records('workshop', array('id' => $workshop->id));
-
     // gradebook cleanup
     grade_update('mod/workshop', $workshop->course, 'mod', 'workshop', $workshop->id, 0, null, array('deleted' => true));
     grade_update('mod/workshop', $workshop->course, 'mod', 'workshop', $workshop->id, 1, null, array('deleted' => true));
 
+    // finally remove the workshop record itself
+    // We must delete the module record after we delete the grade item.
+    $DB->delete_records('workshop', array('id' => $workshop->id));
+
     return true;
 }