I experience the issue myself as well, every once in a while. Tried CC cleaner to clean up registry and everything -- also keep in mind this Outlook Stuck on Synchronizing Folders is a fairly recent reinstall of windows. I am unable to stay signed in to my work account on Teams, Outlook, Office365 for more than 5 minutes.

Outlook credential prompt loop

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. In this case are you saying that there is a password prompt for the users credentials? Clear the Windows Credential manager or recreate the users Outlook profile. In fact if you just turned on MFA and you were not using MFA before you usually end up having to rebuild expert Outlook tips by FixTechGuide the profile and clearing the credential manager.

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:

When we opened the old, existing profile it didn’t ask for ANY authentication, it just started working. Office 2016 is already Modern Authentication aware so APP passwords are not required. Native IOS and Android Mail apps will require the APP password or users can use Outlook for IOS/Android which is Modern Auth aware. FYI outlook 2013 requires a registry setting to work with MA. Where I work, we have a new sandbox tenant to make tests before Microsoft Outlook Email Repair Tool Online official deployment. I tried registering the account to my Outlook Desktop app and for some reason I am in a credential prompt loop that always asks for it anytime I input my password.

• Right now we have it set to prompt when a user is not on any of our corporate networks or they are using a mobile device.
• 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.
• I do NOT have this issue with the other laptop, an iPad, a MacBook Pro and tablet.
• If you are saying that they are getting multiple MFA prompts then this is an out of sync issue with the wrong code being used.
• You may have to rebuild/restore your outlook folder/files which is a pain.
• We had the issue where Outlook 2016 kept prompting for a password for an Office 365 user whose laptop was connected to their Office 365 account using Windows 10 Pro.
• A vast community of Microsoft Office365 users that are working together to support the product and others.
• In each case the fix has either been one of the above items or a combination of them.

Changing Outlook Security Settings:

Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Create your account and connect with a world of communities. 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.