I have been using Thunderbird/Lightning with my Google calendar for years, recently I've had issues. I have a recurring task with an alarm which I cannot dismiss. I removed the task from within the Google web interface, but it won't go away in Lightning. My other Google calendar won't take updates from Google, but any new calendar entries I add in Lightning get synch'd up to Google.
So I'm trying to just remove the calendars in Lightning and start over. I exported the calendars just in case.
I deleted the calendars in Lightning - it pops up a window asking if I want to unsubscribe, I acknowledge and the calendar is gone from Lightning. Repeat for the 2nd Google calendar. The alert pop-up with the un-dismissable reminders disappears too.
I close Thunderbird, re-open, and the calendars I unsubscribed are back, as is the pop-up with the reminders.
How do I permanently get rid of these calendars? Are there files I can remove from the HDD or settings to delete in the Config?
System:
Linux Mint v18.2
Thunderbird v52.4.0 (64bit)
Lightning v5.4
Thanks!
-Brad