It may still be there: Profiles are in c:\users\(yourID)\appdata\roaming\thunderbird\profiles I suggest you start TB, click help>more troubleshooting information. Then scroll down to Profiles, click About:Profiles. Then click 'create profile' and create a name first, and only after that select the browse button to select the profile in the named folder (there may be more than one - yours will be the larger one) and click finish. TB should then be okay if nothing was corrupted. This disassociation sometimes happens when anti-virus programs interact with the software.

David I tried following steps in Thunderbird but don't see option to follow the above prompts. If I go to the help menu then more troubleshooting information the only profile option I have is to open the location of the profile on my PC. I went to c:\users\(yourID)\appdata\roaming\thunderbird\profiles and there is nothing in that folder does that mean Thunderbird doesn't know where to find it or that it no longer is there?

That's puzzling. Next step: look for c:\users\(yourID)\appdata\roaming\Thunderbird\profiles.ini That is the file that tells TB where the profile is. It is a simple text file and can be opened with Notepad or similar software. Anti-virus programs are known to interfere with programs, but deleting the entire profile folder would be extreme.

Avast/AVG users are getting an alert about their prefs.js file, which stores important custom settings for Mozilla software. If you use Avast/AVG, the file may have been quarantined in the past few hours.

It's not yet clear exactly what is triggering the detection, so it's a bit soon to sound an all clear to restore that file from quarantine (if that is an option). Hopefully we'll know more soon.

Avast/AVG users are getting an alert about their prefs.js file, which stores important custom settings for Mozilla software. If you use Avast/AVG, the file may have been quarantined in the past few hours. It's not yet clear exactly what is triggering the detection, so it's a bit soon to sound an all clear to restore that file from quarantine (if that is an option). Hopefully we'll know more soon.

Looks like that was the culprit. My prefs.js file was quarantined this morning unbeknownst to me. I ran a separate scan on that file and found no virus or malware. If I can remove it from quarantine can you tell me where to move it back to so all my settings are back in order or tell me what to do with that file once it's been removed from AVG Quarantine?

Avast forums now say it was a false positive and they've issued a fix --

• https://forum.avast.com/index.php?topic=318639.msg1683272#msg1683272
• https://forum.avast.com/index.php?topic=318640.msg1683270#msg1683270

-- but unfortunately, we still have to clean up the damage by restoring the file to its original location.

Does Avast have a feature for this in its quarantine?

The original path on disk would have been listed in an alert. If Avast shows historical alerts, and you can get the file back, then you could drop it back in that folder (and replace the new one without any useful information in it that most likely was created there the next time you started Thunderbird).

Avast/AVG users are getting an alert about their prefs.js file, which stores important custom settings for Mozilla software. If you use Avast/AVG, the file may have been quarantined in the past few hours. It's not yet clear exactly what is triggering the detection, so it's a bit soon to sound an all clear to restore that file from quarantine (if that is an option). Hopefully we'll know more soon.

Thanks for the info.

Swapping out the prefs.js file appears to have reverted everything to pre-quarantine status.

I had the exact same problem. But restoring the profile did not resolve the lost accounts and emails! What should I do???

I had the exact same problem. But restoring the profile did not resolve the lost accounts and emails! What should I do???

Could you start a new question, this one is already marked as solved. Here's the link:

https://support.mozilla.org/questions/new/thunderbird/form