Thunderbird has to be reset every time it opens.
3 Days ago Thunderbird, Firefox and Windows 11 all updated at the same time. Now, every time I close and reopen Thunderbird, it takes me back to the "Setup your existing email" page, and I have to create a new profile and start over. I then restore my email and settings, etc. via a backup, only to have the same thing happen the next time I open Thunderbird. Firefox is being similarly affected, but not quite to the same degree. I don't lose my bookmarks, but all my settings have to be restored. I'm using Bitdefender Total Security, and have turned everything off, and the same thing happens. I've been using all these programs for years, and Windows 11 for over a year with no problems. Please help.
Opaite Mbohovái (2)
Start Windows in safe mode. If it stops happening then you have a problem from some other software, like Bitdefender.
https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
Thank you, Wayne, for this response. I did as you suggested, and Thunderbird and Firefox appeared to work properly. I then uninstalled Bitdefender and rebooted. Now, running Windows anti-virus and firewall, Thunderbird and Firefox seem to be behaving, so it appears that Bitdefender may be the culprit. I have all the same programs and versions, including Bitdefender, running on a laptop, using Windows 10. Everything has been working smoothly there. So, my next question is, is it a conflict involving Windows 11? And, if so, how can I resolve it?