P.S. The Thunderbird I downloaded was Version 91.2.1 which appears to be the newest version since it was released just 2 days ago. I'm guessing info in the folder I'm trying to import is from an older version (since I've not been able to use Thunderbird so didn't get the update to 91.2.1). I tried downloading an older version, thinking I could copy the folders & emails over and then update it, but am getting the same message as shown in my original question. Can someone please tell me which file(s) in my backup can/can't be imported so I can pick & choose which ones to copy over instead of doing them all? Obviously something there is blocking it but I don't know which... UPDATE: I finally gave up and did a roll back/restore to a few weeks ago BUT... Now when I click to open Thunderbird I get a pop up that says Couldn't load XPCOM. I've looked for a fix for that but it brings me back to uninstalling and re-downloading which will bring me right back to my original problem. PLEASE can someone help me???

Well, I tried it, I downloaded 91.2.1 and let it update the one got back with the restore but that gave me the error I originally wrote about. Figuring I had nothing else to lose, I downloaded 94.0b4 and let it update to that. That did indeed fix the XPCOM issue and gave me back all my accounts and folders! WooHoo!! However, I'm right back to my original issue of Thunderbird downloading all my emails back to 10/11 over and over again. I have one email that is completely blank, and I suspect that is causing the problem because when that appeared is when it started repeating the emails. But I don't know how to get rid of that or fix this problem. I get tons of emails every day so it takes longer and longer to delete 10 days worth, then 11 days worth, then 12 days worth. And if I check for new mail several times a day, it downloads all of those several times a day!

go to your mail provider in a browser and empty the spam folder and trash. That usually has a good effect on getting rid of malformed emails and stops the anti virus messing you around with restarting the downloads.

Hi Matt, and thank you for replying  :) I have been going to my email on their webpage daily and deleting everything from inbox, spam and trash. I called them to see if my emails were not being deleted from the server but they said they were. In my search for help I did read that my antivirus might be causing it, so I set that to not check my emails, but it didn't help. Same ones still keep downloading... I have also made sure Thunderbird is set to NOT leave messages on the server. Do you know of anything else I can try?

Really I have no idea where you are now. But I would like you to install V91.2.1 from thunderbird.net so at least we have that part of the playing field working the same. As you are downloading the most recent release version you should not see issues with old profiles, unless your previous installation was a beta or even daily build.

Remaining on beta (which will make reusing the profile you are currently using very difficult I hope you still have that backup.

Issues with xpcom, I really do not understand those, and it is usually telling you the versions that are the same are incompatible. However a reinstall of a fresh download has fixed that for everyone I have dealt within the past with the issue. I guess some DLL just does not get registered right occasionally.

RE download? or just re displaying years old data because you have never compacted to allow the program to discard it. Lets see. Open the file menu and select compact folders.

Thanks again, Matt :)

When I downloaded 91.2.1 it said it wasn't compatible to import my old profiles. So I downloaded the latest beta I could find, 94.0b4 and that did pick up my original folders & emails. It also took away the XPCOM error. I'm afraid if I try to downgrade I will run into the issue again of a newer version having made changes that are not compatible... Another solution I read about was to change my email settings from POP to IMAP so I created a new profile using my main email and a little change in the name. That seems to have stopped it from downloading the same emails over and over. So now I'm working on moving emails I want to keep into local folders so I can safely delete anything still on the server but it is a very VERY SLOW process... As for compacting, I do that on a regular basis. I am also deleting a lot of the old emails that I had held onto that I don't really need anymore. But again, that is VERY slow. So this is going to be a long on-going process. But hopefully, at the end of it all, I will finally be able to make use of Thunderbird again!