http://kb.mozillazine.org/Recovering_a_profile_that_suddenly_disappeared

Do you use the program CCleaner? What antivirus are you using? What version of Thunderbird do you have?

Airmail said

Do you use the program CCleaner? What antivirus are you using? What version of Thunderbird do you have?

Hi, yes I do use CCleaner. Hmm, in fact installed the latest update this morning (ver. 5.31.6104). Hadn't thought of that ... And interesting that I opened CCleaner to get the version number and immediately had a pop up to download the latest version 5.31.6105 -- not 7 hours later. For AV running Win10 so using Windows Defender. Thunderbird version is 52.1.1 (updated last month)

CCleaner is at fault - my advice, set CC preferences to NOT touch Thunderbird and Firefox - it's totally unnecessary.

https://forum.piriform.com/index.php?showtopic=48428&p=284171

Airmail said

http://kb.mozillazine.org/Recovering_a_profile_that_suddenly_disappeared

Doing my replies a little backwards here -- sorry about that - but did open the link: Recovering a profile that suddenly disappeared a in going through it, finally determined my pref.js file has been corrupted - none of the necessary mail mapping entries. Now trying to figure out how to restore just the TB profile file from a backup last month using Dell backup. Looks like may have to pay for the premium version to just recover/restore a single folder instead of whole system?

Wayne Mery said

CCleaner is at fault - my advice, set CC preferences to NOT touch Thunderbird and Firefox - it's totally unnecessary. https://forum.piriform.com/index.php?showtopic=48428&p=284171

Been using CCleaner for years with no problems so never would have thought it would be the culprit on this bizarre happening. But will take your advice going forward. I do fine it "interesting" that they came out with new, updated version in less then a day?

> I do fine it "interesting" that they came out with new, updated version in less then a day?

That's because they screwed up ;)

Looks like I found a way to restore my TB profile folder from the Dell backup I did last month. Don't want to lose email so copied the Mail folder to another folder. Anything else I need to pull out and save before overwriting the current profile folder? I've been down most of the day and use TB for both personal and my business emails. Not good! Thanks!!

if that backup has a msgFiltersRules.dat file save and copy it over save yourself countless hours rebuilding your filters

for imap would be in:

/Users/{USERNAME}/AppData/Roaming/Thunderbird/Profiles/{soemhash}.default/ImapMail/imap.email.provider/msgFilterRules.dat

Thanks Wayne, like others, I've been using CCleaner for years so would not have thought of that, tip much appreciated. Johna888

Many thanks - yes I suspected CCleaner - especially after the very quick update to the update. Now to set about trying to get it all back. I do have complete backups, from no more than a week os so ago, so that should help.

According to some reports, the only thing you might be missing is prefs.js

If that is true in your case then you could copy just the file back and not lose any other changes since your backup

Wayne Mery said

According to some reports, the only thing you might be missing is prefs.js If that is true in your case then you could copy just the file back and not lose any other changes since your backup

Thanks Wayne for your great help! Finally got everything back last night. Panicked a minute after I pasted in the older/good prefs.js file from my backup and it's still opened with the setup screen. It also made a new "bogus" profile. Deleted the new profile and then used the profile manager to rename/point it to my original. That did the trick. Apparently it had to create the new ini file? Thanks again!

Airmail said

http://kb.mozillazine.org/Recovering_a_profile_that_suddenly_disappeared

Wanted to also thank you Airmail for your help yesterday. Thank you!! The link you provided was a great help! Finally got everything back to normal last night

I'm still unable to get my list of newsfeeds back. If it's possible to restore the list, where would I look for it? Thanx!