Have "Provider for Google Calendar" to access my Google Calendar. But since summer I can not longer access the google calender after every Thunderbird update. This is really annoying. The only way to solve this problem is to: 1. To unsubscribe from any Google Calendar 2. Deactivate the Add-on "Provider for Google Calendar" 3. Stop Thunderbird 4. Delete the files cache.sqlite and deleted.sqlite from the folder calendar-data inside my profile 5. Restart Thunderbird 6. Reconfigure my calendar Does anyone know what to do to prevent Thunderbird to destroy my calendar access during update? Have currently 78.5.0 (64-Bit) Best regards André