Thunderbird calendar doesn't save events

Question

I have a hosted email service that I access via Thunderbird.

Currently, new events that I create in Thunderbird do not show in my calendar in Win11.

I create an event:"New event">enter details etc>"save and close" and there's nothing there.

I'm using v115.2.2

What I've tried:

• I've synced the calendar.
• I've removed and re-added the calendar, the issue persists.
• Attendees I add to the event also do not receive any notification.

When it kind of, not really works:

• Weird, when I set the event to "all day" it will appear in my calendar. If I set the time/duration to anything else, it does not appear. Editing an "all day" event to (for example) 12-1pm doesn't make it appear.
• When I create an event via the web interface of my email client's calendar, it appears in the Thunderbird calendar.
• When someone invites me to an event and I accept, it gets added to my calendar.

Answer 1

I had the same problem on 115.9.0 (64-bit) on Linux Mint 21.3, where my local calendar was not working either. Remote calendars were working fine, too. Luckily, I found a solution working for me.

I browsed to the folder holding my calendar data for Thunderbird. It is at

/home/username/.thunderbird/wwhw2y0m.default/calendar-data 

(Note: this is just an example path).
If Thunderbird is not running, you should see three files called cache.sqlite, delete.sqlite and local.sqlite. For me, there was a fourth file in the folder called local.sqlite-wal with 0 bytes in size. I deleted this file and restarted Thunderbird. Et voilà, my local calendar was back and working as expected.

This extra file, which is only there if Thunderbird is running, was probably an artifact from a previous session that was not automatically deleted, causing the hiccup.