Second time is a charm. Manually deleted the track (via filesystem), restarted CM, allowed it to download the update from the notification (was still there), installed from the notification, and restarted CM. No more update notification, version in ui_track.json files is 1.11You did close ContentManager at least once ? If it still wants to update after a restart, close CM again, update track manually from 1.11 link, then start CM.