To start Outlook in safe mode, press the Windows key on your keyboard. In the search box, type outlook.exe /safe, then press Enter. If you've changed your password on the website for your email account, you'll need to change it in new Outlook, to If memory serves me right, modern auth with 2fa, and being a GA and using the account for outlook are known for issues. If you have an issue that's not listed in this article, go to the following Microsoft TechNet wiki page. The wiki page lists oth...