Gmail does its own thing, but try this: - click settings>privacy&security' - click 'saved passwords' and then'show passwords' - highlight the two rows for that account and delete them - that removes the OLD gmail password - now try again to receive messages and that may generate the google prompt for new password.

Thanks David. Unfortunately that didn't do anything. The passwords are showing as blank.

This is really weird. On the page "Set up your existing email address" the "checking password" box still has a green blob bouncing left to right. It then triggers the Google pop up screen with the same message. I can't seem to do anything.

Is there a way to reset Thunderbird or Gmail? It was obviously fine before but now for some reason it is 'polluted' with something. If you want me to send any other diagnostics or screengrabs please LMK

this may work: - exit TB - delete logins.json, key4.db, and cert9.db (or rename them) - restart tb and attempt to connect.

Thanks David. Unfortunately that didn't solve my problem and now it's had other problems. I had 2 other Gmail emails and they're now all acting the same way. I cannot reset or work with any of them.

Is this the end of the road? It's a shame if trying to reset my password for Gmail means I can't use Thunderbird at all.

Any other ideas from anyone? I've just made a donation to Thunderbird after finally ditching Outlook. Now I'm stuffed!

Please look at this thread, as the problem is the same, but a different suggestion is being offered there:

 https://support.mozilla.org/en-US/questions/1447519   The person making suggestion is sfhowes, highly respected here and his approach is different. I'll be watching it too. In summary,  he is suggesting to delete and re add the account and to place password where you would normally enter the OAUTH2 authentication setting. I'll be watching it too, as Gmail setup seems to change periodically. I won't leave you until a better answer is done.  https://support.mozilla.org/en-US/questions/1447519

Thanks David. It hasn't solved my problem. Maybe I'm not doing it right but the instructions don't clearly map to the problem or what I'm seeing.

I go to Server Settings the Authentication Methods (this is the only place I can find a reference to OAuth and I change "OAuth2" to "Normal Password" which also triggers Connection Security to go to "SSL/TLS". I tried "Encrypted Password" first but that didn't work.

When I try to connect I get "Login to server imap.gmail.com with username dan@dansomers.com failed." then I get a pop up saying "Application-specific password required" and a google URL.

I do not know what I'm doing or what is going on. I do not have two passwords. I only have one which is the email (account?) password.

If you can be really prescriptive about which buttons and menus I need to press that would be great.

Here is what I do and it has worked for me: - delete account - exit thunderbird and restart - check settings>privacy&security to be sure that cookies are accepted - create the gmail account but OMIT the password. Thunderbird has the normal settings if IMAP. - when checking for mail, google prompt should ask for password. after that, a screen will appear with ALLOW button. Check that. - normally, that is all I need.