Whoops. I even tried MozBackUp and that didn't work either. Morgan Bilbo, Tb60.

See if this article helps. https://support.mozilla.org/en-US/kb/calendar-updates-issues-thunderbird

FYI: Per the author of Mozbackup, the add on is broken so use at your own risk. http://mozbackup.jasnapaka.com

So. The bottom line is I'm OOL. And Tb/calendar is a bummer. I know for a fact that most other calendars are no better. So it's back to pencil and paper. Pencil because it has an eraser. Pens don't. And online was great for corrections and keeping track. So now there's no use in using a PC for watching for important dates and such. And if I make an appt. over the phone and when I have time, put it online, I'm OK. But now, all that info is gone and I have to try to reconstruct it. WHEW! An almost impossible tack. As for MozBackUp, what is there to store a calendar info? Windows is a joke. Yahoo is too. Even trying Sticky Notes is awkward. There's no "events list". If this ends this, so be it.

I do not see a bottom line in my post anywhere. Did you do what the article said to do.

All your data is stored separate from the program in your profile. Start making backups. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

OK Airmail. I apologize. First, I already tried that link you supplied. The link you first supplied had already been done. i.e. The "extension" situation in "config editor". I had never done a back up per your latest. I can do that now, but that's shutting the barn door after the horses got out. i.e. Is there a way to restore the old calendar/i.e. INFO. I do have the calendar, just that it's blank. I'm trying to make this clear. The link on "how to backup" is way over my head. I don't even begin to understand. When I go to "backup", it says to shut down Tb and "locate your profile" - as above. ???? That is not simple to me. But I'll give it an honest attempt. And get back here after I see what I can do. I am not PC proficient. I'm just a normal user of Tb for email and such. The calendar was an option I chose. And now wish I hadn't. Later, Morgan Bilbo

Wow! Talk about stupid instructions. First it says locate the profile. OK. Then it tells you how to find the correct file which is total gumbdee goop to me. "we5llfeh.default". Then it says to copy/paste onto a USB or CD-RW. But it don't let you know how big. I had to dig around to find a USB stick large enough to hold this file. 8.3 GB. How many people have a flash drive that large just laying around for you to backup a profile? I was lucky I had a 32 GB stick that was not full and could hold this 8.3. (and of course, 32 is actually 30 and that restricts what you can do. This PC stuff is too much for a 79 yr old man trying to have a PC to keep track of doctor appts. And now it's over 1/2 hour and the process shows 23% complete. What a dumb way to back up. More to follow.