This is fixed in TB 68.2.1 for gmail IMAP accounts, but for earlier versions, apply the workaround mentioned here:

https://bugzilla.mozilla.org/show_bug.cgi?id=1592407#c22

Tools/Options(Mac:Preferences; Linux:Edit/Preferences)/Advanced/General/Config. editor, double-click general.useragent.compatMode.firefox to true.

Make sure you don't have any old passwords in Tools/Options/Security/Passwords/Saved Passwords.

This should also fix google calendar and contact sync. in 68.2.1 until updated Provider and gcontactsync add-ons are released. (The Provider add-on has been updated.)

Thanks. That worked!

I have cleared all passwords that I can find. Obviously, Thunderbird has access to passwords of which I am not aware. Apart from preventing me using Thunderbird, is that a security risk that you don't wish people to know about?

davidgreen1204 said

I have cleared all passwords that I can find. Obviously, Thunderbird has access to passwords of which I am not aware. Apart from preventing me using Thunderbird, is that a security risk that you don't wish people to know about?

TB doesn't store any passwords besides the ones entered by the user. Occasionally, a request for a master password appears when one hasn't been set, but that is easily fixed by deleting the relevant files in the profile folder. If an external password manager, the kind that are provided with some security apps, is present, that can interfere with connections to email accounts.

Thanks for your help but I am not the holder of a degree in computing. If I knew whether this was the Chrome profile, TB profile, or Gmail profile and where to find them, things may be OK.

All I did was update Chrome and it stopped Thunderbird working on Gmail but Yahoo mail is fine.

So you are saying this is definitely an issue with Chrome despite Google and Chrome saying it is TB problem.

It seems as long as people say ring/call/contact someone else that solves the issue.

I am ready to stop using TB, Chrome, and Google but not sure if I can recover emails stored in TB local folders.

Gmail says select POP and change it to IMAP but TB says it does not support Google IMAP. I know enough to say that one of them is wrong, but not enough to know which one or what to do about it.

I have now tried using POP setting on TB but it insists on using IMAP as a default despite claiming not to support Gmail.IMAP. Totally confused.

Now removed Gmail from TB and tried to enter new email.

TB sets up data it has found and then says it is unable to access it.

Seems quicker to wait for Haley's comet than get an answer on here so after another 24 hours it is goodbye to Google, chrome, and TB.