But by mistake, I turned on MFA for the admin account, and then when I logged in again, it prompted me to use Microsoft Authenticator. The bad thing is this account was not registered with Microsoft Authenticator, so I couldn't see any codes diagnose Office activation conflicts in the authenticator. And there were no other login options, and I was stuck in a login loop. 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.

Outlook credential prompt loop

I disabled the Zoom and Adobe PDF plugins and it stopped prompting me immediately. My client’s Outlook will only continuously ask for the password solve Office 365 mailbox sync delays after MFA is enforced and Office.com has been logged in. It would be nice if it distinguished between your password and the app password. You may have to rebuild/restore your outlook folder/files which is a pain. I’d do that one step at a time, forgoing the restore of the cached files. Not sure if it has to do with being an onmicrosoft.com account that has no domain assigned to it.

Loop of 'Sign in to your account'.

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. Yeap, you describe it exactly and unfortunately we still don’t have an answer. Closed the window without entering anything and Outlook returned to ‘Connected to Exchange’. I created a new Outlook profile, and then the old one started working. I wonder if the compuer cached a new logon token or something that the old Outlook profile could use. Also, during the new profile creation, I was only prompted for a password and not for MFA.

Resetting the Windows Credential Manager:

I have contacted my organization and everything looks alright from their end.. I went as far as getting a new device but it did not cut it. When I try to sign again it will be stuck in sign in loop with the message " Taking you to your organization sign in page" after I have logged in on my company site... When I log in to my account at first from a new device or after a while, it stays signed in and I can work peacefully for about an hour, then it automatically signs me out. Or, any suggestion on how to fix this issue, even guide to Office 365 sign-in errors better. I do NOT have this issue with the other laptop, an iPad, a MacBook Pro and tablet.

• If this box is greyed out or disabled then you need to reset the Windows Credential Manager first.
• FYI outlook 2013 requires a registry setting to work with MA.
• Out of 140 staff the problem seems to occur once every 2-3 weeks on average.
• But by mistake, I turned on MFA for the admin account, and then when I logged in again, it prompted me to use Microsoft Authenticator.
• I'm also getting Error 29, which the MS support rep couldn't explain to me.
• I experience the issue myself as well, every once in a while.
• I’ve seen this happen when the time and or date is wrong on the machine.

Changing Outlook Security Settings:

If this box is greyed out or disabled then you need to reset the Windows Credential Manager first. @Microsoft, given the level of attention the community has given this issue, I hope you come up with an update soon. We have been experiencing the exact same issue for months now.