Index: lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20210927.sql
===================================================================
diff -u
--- lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20210927.sql	(revision 0)
+++ lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20210927.sql	(revision 311592201076cbd35231d16a61b8f558fd5261bd)
@@ -0,0 +1,16 @@
+-- Turn off autocommit, so nothing is committed if there is an error
+SET AUTOCOMMIT = 0;
+SET FOREIGN_KEY_CHECKS=0;
+-- Put all sql statements below here
+
+--LDEV-4288 Prevent duplicate entries
+
+ALTER TABLE lams_gradebook_user_activity DROP KEY activity_id,
+										 ADD UNIQUE KEY UQ_lams_gradebook_user_activity_1 (activity_id, user_id);
+
+-- Put all sql statements above here
+
+-- If there were no errors, commit and restore autocommit to on
+COMMIT;
+SET AUTOCOMMIT = 1;
+SET FOREIGN_KEY_CHECKS=1;
Index: lams_common/src/java/org/lamsfoundation/lams/learningdesign/ToolActivity.java
===================================================================
diff -u -r423858087ec4d185fb33c3f569fc7ede1d43001a -r311592201076cbd35231d16a61b8f558fd5261bd
--- lams_common/src/java/org/lamsfoundation/lams/learningdesign/ToolActivity.java	(.../ToolActivity.java)	(revision 423858087ec4d185fb33c3f569fc7ede1d43001a)
+++ lams_common/src/java/org/lamsfoundation/lams/learningdesign/ToolActivity.java	(.../ToolActivity.java)	(revision 311592201076cbd35231d16a61b8f558fd5261bd)
@@ -128,18 +128,6 @@
 	    newToolActivity.setEvaluation(newEvaluation);
 	}
 
-	Set<GradebookUserActivity> newGradebookUserActivities = new HashSet<>();
-	if (this.gradebookUserActivities != null) {
-	    for (GradebookUserActivity gradebookAct : this.gradebookUserActivities) {
-		GradebookUserActivity newGradebookAct = new GradebookUserActivity();
-		newGradebookAct.setActivity(newToolActivity);
-		newGradebookAct.setLearner(gradebookAct.getLearner());
-		newGradebookAct.setMark(gradebookAct.getMark());
-		newGradebookAct.setUpdateDate(gradebookAct.getUpdateDate());
-	    }
-	}
-	newToolActivity.setGradebookUserActivities(newGradebookUserActivities);
-
 	if (this.plannerMetadata != null) {
 	    PedagogicalPlannerActivityMetadata plannerMetadata = this.plannerMetadata.clone();
 	    plannerMetadata.setActivity(newToolActivity);