Your emails should still be safe, as they are stored elsewhere. If you use File Explorer and browse to c:\users\yourID\appdata\roaming\thunderbird\profiles\ you should see your profile, and in the profile are two important folders: Mail (for POP mail) and Imapmail (for IMAP mail). There may have been an error in the update process.

ok David, so the emails should still exist, but I have no way to access the emails. I need Thunderbird to get fixed so that I can run the program and get back into the emails.

I did end up finding the same problem on here from a year ago, but the error path was different (but same error title) and the only reply was to try reinstalling the program. I did that & it not only works, but I did not even have to reenter my email info. Provider, address, passwords......None of that! Yet it all came right up, even though installed in a totally different hard drive location.

Reinstalling was my intent. Everything worked because the reinstall saw the same profile. I'm glad it all worked out okay. If you're content, please close this post so it gets removed from active list. Thanks.

Sorry David, but no. I won't delete it as leaving it will show it forothers in the future, like whatI found tosolve the problem. It is a good thing to leave posts up to be found, to help others through searches like I found one.