I am setting up Thunderbird on a Win10 machine, and am having a lot of trouble adding accounts that I did not have on the two Win11 machines I have set the same accounts up on. When adding my 2 GMail accounts, after clicking "Allow" on the OAuth popup the button would go grey the window would stay open and not close, and the account would not be added. Changing the general.useragent.compatMode.firefox option to TRUE allowed me to progress and finally add those accounts. I am now having the same trouble with my @hotmail.com account. When I add the account, the dark blue OAuth window pops up, but is completely empty, and there is nothing more I can do. Things I have tried * Reverting the above config change * Checking that cookies and JavaScript are enabled * Checking there is no saved password * Used both the Account Hub and the default dialog, with the same effect. Thanks in advance!