AOL as I understand it moved to oauth authentication shortly after their happy marriage to yahoo.

Try changing the authentication method in account settings.

AOL accounts work with either normal-password authentication or OAuth2. When you say the password is 'programmed in', does that mean you're using something else besides TB to manage passwords? It may be part of your security/AV program, and possibly the source of the problem.

I have the password in TB. Not using something other than TB. I've had it this way for many years with no problem. I went into the server setting and noticed the oAUTH2 option...which you mention as well. So, I switched to it...and it seems to be working better. Not that that solved the original problem Buy anything to get Thunderbird to synch and display the emails without that annoying message box poping up every 30 seconds.