Unit tests provided. Setup Uninstall your current instance. Check out an older version of the branch that you're testing (e.g. if you're testing on 3.6, you can do git checkout v3.6.0 ) Install this Moodle instance Set up the following 3 courses (C1, C2 and C3) with 2 forums in each of them A user (admin is fine) enrolled in the courses "Recently accessed items" (RAI) block added on the Dashboard As the user, go to each of the forums in the courses. Go to the dashboard and confirm the 6 forums appear in the RAI block Delete course C3 Delete a forum from C2. Test 1 - Upgrade Checkout the branch that you're testing (e.g. if you're on 3.6, " git checkout MOODLE_36_STABLE ") Upgrade your moodle instance. Confirm that upgrade completes successfully and you don't see any errors. Go to the Dashboard Confirm that you don't encounter any errors. Confirm that the forums from C3 are no longer being shown in the RAI block. Confirm that the forum that you deleted in C2 is no longer being shown in the RAI block. Test 2 - Deleting courses/activity modules Check the RAI block on your Dashboard. You should see 2 forums from C1 and a forum from C2. Delete course C2 Delete a forum in C1 Go back to the Dashboard Confirm that you don't encounter any errors. Confirm that the forum from C2 is no longer being shown in the RAI block. Confirm that the forum that you deleted in C1 is no longer being shown in the RAI block.