
Thunderbird does not shut down completely, even with a cold shutdown.
I cannot start Thunderbird, because a message pops up, saying Thunderbird is still running and to shut it down first. I click the shutdown button, but it does not do a shutdown. I tried shutting it down with Task Manager, but that did not stop it. I tried turning the computer completely off and waiting 30 minutes, but that did not work.
Wšykne wótegrona (2)
Try this:
Close TB and open the Profile manager. Select the profile you want to use by default > check 'Use the selected profile...' > click 'Start Thunderbird'.
Also make sure TB menu > Settings > General > System Integration > 'Always check to see...' is enabled and click the 'Check Now' button.
Does removing the profile lock make any difference?
https://kb.mozillazine.org/Profile_in_use#Remove_the_profile_lock_file