Also, at the time, that user did not have MFA turned on. In the instances that this occurs the effected user is not new to MFA but has been running it for at least months. The problem appears to randomly affect users (I’ve had it affect myself once too), and the only solution appears to one of (or a combination of) the options in the OP. Out of 140 staff the problem seems to occur once every 2-3 weeks on average.

Additional resources

This is now the 2nd machine that presents the same issue. I have a valid MS 365 subscription that includes 5 device licenses. On the main machine where I have been using the suite, now my account is deactivated and if I try to authenticate, it looks like it works but then get the "Fix", "Authenticate", "Activate" or "Resolve" buttons, all of which do nothing. I checked my MS account info page, subscription is fine. I had this exact issue on another machine, that after 2.5 hours on the phone with MS support (via Zoom), the solution was to uninstall MS Office 365 and reinstall it.

Microsoft Office 365 Endless Authentication Loop Issue

• I cannot find the phone number again to contact MS Office support (eventually they were helpful, but only after insisting they help!), I'm in the Netherlands so if someone has a phone number, I'd love to get it again.
• Before you access it, back up the registry for restoration in case problems occur.
• On the off chance that none of these things solve this issue for you, please contact our support team at
• Clear the Windows Credential manager or recreate the users Outlook profile.
• The connection to Microsoft Exchange is unavailable.
• We checked with Word that the account was connected–it was and the we opened Outlook and it immediately connected.
• Office 2016 is already Modern Authentication aware so APP passwords are not required.

You may have to rebuild/restore your outlook folder/files which is a pain. I’d do that one step at a Fix Outlook and Office365 Sync Issues time, forgoing the restore of the cached files. If this box is greyed out or disabled then you need to reset the Windows Credential Manager first. Or, any suggestion on how to fix this issue, even better.

Outlook stuck in an MFA loop

I do NOT have this issue with the other laptop, an iPad, a MacBook Pro and online Outlook email repair utility tablet. So figuring that was the same issue here, I did the same thing. I'm also getting Error 29, which the MS support rep couldn't explain to me. I even tried disabling my anti -virus while authenticating, that didn't work.

Outlook 365 Password Prompt Issue on Windows Desktop

Microsoft Outlook 2016 and some recent builds of Outlook 2013 are not affected by this issue. Those versions have been updated to prevent the problem that is described in the "Symptoms" section. These versions have the Logon network security setting disabled or removed from the Microsoft Exchange email account Outlook stuck updating folders solution settings. It requests me to login to my microsoft account. I then approve the login with my authenticator app. Then i get rerouted to the login page again to repeat the process.