the issues in migrating a profile from Linux to windows and back are largely in the way paths are written. \ in windows and / in Linux.

However, just a guess but try deleting the pkcs11.txt and starting Thunderbird in safe mode.

Hi I took a look at the pkcs11.txt file before deleting it. It had the old Windows profile path in it, with backslashes. After deleting it, and reopening Thunderbird, the problem was solved. I didn’t need to open it in safe mode. The file was recreated with the Linux profile path in. All good! Thanks very much! Steve

Just wanted to add my experience. I was simply migrating Thunderbird from PC Win7 to Mac OS High Sierra and ran into this problem. I tried all the other fixes by deleting various files from the copied profile without success. A quick look at the pkcs11.txt file made it all very obvious. The Win7 directory paths were in there pointing to nothing relative on the Mac. So following the instructions above fixed the issue for me. I checked the pkcs11.txt file before even restarting TB and I could see the new Mac directory paths. One thing I can't be sure of is if I had to even delete the other files ("cert8.db" and "key3.db") as I had already done this trying other fixes. In any case it seemingly didn't hurt as everything seems to be working fine now. Moral to the story...different platforms will have different file paths and directly copying your profile folder will (now obviously) require this fix to be carried out. Thanks so much for this...I was pulling my hair out!!

Same issue going from Windows 7 to Mint but deleting the txt file did not fix the required constant login to check my TB mail after updating the profile with the Windows one. I assume after installing TB and launching it to create the .thunderbird directory I shouldn't answer the pop-up login question but just close TB and then copy the Windows profile directory before relaunching. If I do log in and set up pop server email/pw before shutting TB down and copying the profile, the old folders don't show up though TB works.

Your mileage may vary but I didn't need to log in and set up the pop server email/pw. All that information was in the profile folder that I copied across. The problem for me was that Thunderbird couldn't find the info it needed due to the paths that were incorrect in the pkcs11.txt file. I deleted that, while TB was closed, then on reopening, I had to put in the passwords again, but that was for the last time.

Steve

Thanks Steve. I did delete pkcs11.txt and was able to bring up my old Windows folders in Mint. At this point I have to log in to check my mail the first time after launching TB and the first time I try to send an email. After that I'm good till I shut TB down, re-launch and the cycle starts again. I can live with the single login per day.

That is annoying! It might be worth starting a new thread with your specific problem if you don't get an answer here.

I will consider starting a new thread. I will give it a few days...