OSX 12.7.4 I upgraded to 115.9.0 to get OAuth for some, but not all, accounts. Those on Gmail & Yahoo are OAuth. I have non-OAuth accounts on a Zimbra server, and on Panix.com. It prompts for the first account's password. TBird then gobbles '''all '''available CPU on the machine, and stays there. If I wait long enough, it becomes usable again, but that may well be hours. However, once it calms down, it works normally. Intertwined with this is: TBird rejects the Zimbra passwords as I enter them. I retry and retry, and then they succeed. I know the passwords are correct; I've even typed them out, and then copy&pasted them in. I'm not sure about the Panix account, if its password works the first time or not. I tried restarting in troubleshooting mode; it made no difference.