Unable to delete checklist mod

We updated to 2.9 a few weeks ago and I have am no longer able to delete a checklist from a course,

Message:

Default exception handler: Can not find data record in database table event. Debug: SELECT * FROM

WHERE id = ?\n[array (\n 0 => 7948,\n)]\nError code: invalidrecord\n* line 1453 of /lib/dml/moodle_database.php: dml_missing_record_exception thrown\n* line 1429 of /lib/dml/moodle_database.php: call to moodle_database->get_record_select()\n* line 2645 of /calendar/lib.php: call to moodle_database->get_record()\n* line 2518 of /mod/checklist/locallib.php: call to calendar_event::load()\n* line 2675 of /mod/checklist/locallib.php: call to checklist_class->setevent()\n* line 2314 of /mod/checklist/locallib.php: call to checklist_class->deleteitem()\n* line 590 of /mod/checklist/locallib.php: call to checklist_class->process_edit_actions()\n* line 35 of /mod/checklist/edit.php: call to checklist_class->edit()\n,