Gmail imap retrieval stopped working two days ago

[udippel]

I haven't changed any settings at all, no updates (that I know about). For the last two days the password prompt - which is set to be stored, and had not been asked for ages - was asked for, and even if I put the correct one, the password prompt comes back repeatedly. So I can't read my mails via IMAP these days. For the rest, Gmail works fine, also with the gmail client on my tablet.
Since I didn't do any modifications, I wonder what could go wrong here. The settings haven't changed, and should be okay, since the password prompt comes up repeatedly.
I have checked the password for changes by logging into the web interface, without any problem.

[tanstaafl]

Try deleting the saved password, exiting, restarting and trying again. There is a bug where a known good password always fails after a hard connection failure - that works around that.

[LuckyEddie]

Same here. Multiple accounts all failed at the same time. TB 52.9.1 on Mint. Deleting and re-adding accounts also make no difference. Doesn't get as far as the pop-up for Google login.

[DanRaisch]

See the reply above from tanstaafl.

Go to Edit → Preferences >SECURITY > PASSWORDS tab> SAVED PASSWORDS button and there you can delete old passwords for those accounts. Restart Thunderbird to ensure that the stored password is cleared from memory. The next time you "Get Mail" Thunderbird will ask for the password and you can check the box to remember the value.

[LuckyEddie]

That didn't help my situation. It seems that whatever occurred corrupted the TB installation. Saved Passwords showed as empty and then I had repeated TB application crashes. Filesystem checked as clean. Uninstall, removal of profile and reinstall seems to have cleared to issue.