Issue: Some users with Outlook 2016 for Mac have gotten into a login loop and cannot access their mailbox, despite entering the correct password.
- Solution for MacOS:
- Close Outlook
- Open Microsoft Excel and log on to Office 365. (You may need to log off Excel first, then log in again to force reset)
- Once Excel is logged on properly to Office 365, re-launch Outlook.
- Solution for iOS:
- Update iOS to the latest (currently 10.2.1.) if the hardware is new enough to support it. (Older hardware, such as the first gen iPad or first gen iPad Mini will not update sufficiently).
- Update Outlook for iOS to the latest version in the App Store.
- If Outlook is prompting for signing on, go into Settings > Select the account > Reset Account.
- If that fails, Delete the Account and re-add it