Confirm, it occurred using TB internal calendar (formerly Lightning) not any external calendar.
Reinstalling TB 78, restoring profile, then exporting calendar and importing that into TB 91 recovered it.
It's an update problem.
Richard
Confirm, it occurred using TB internal calendar (formerly Lightning) not any external calendar.
Reinstalling TB 78, restoring profile, then exporting calendar and importing that into TB 91 recovered it.
It's an update problem.
Richard