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. To locate and view the registry setting for Anonymous Authentication in the Outlook profile, follow these steps. This issue can occur if the Logon network security setting on the Security tab of the Microsoft Exchange dialog box is set to a value other than Anonymous Authentication. Today was the first time in about 2 months that I had the issue. It happened right before lunch, locked my machine, went out for lunch, came back, and logged in, this time successfully.

Additional resources

Please help can't afford a new computer if I throw this one against the wall. 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’. Office 2016 is already Modern Authentication aware so APP passwords are not required.

Microsoft Office 365 Endless Authentication Loop Issue

• I even tried disabling my anti -virus while authenticating, that didn't work.
• Microsoft Outlook 2016 and some recent builds of Outlook 2013 are not affected by this issue.
• We have been experiencing the exact same issue for months now.
• If this box is greyed out or disabled then you need to reset the Windows Credential Manager first.
• Unfortunately when the problem occurs they’ve asked us to ring straight away but of course you can never get them instantly (we’ve just been given someone’s direct number now).
• 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.
• The repeated issue logging in started after I enabled the modern authentication in the Office 365 administration panel.
• In fact if you just turned on MFA and you were not using MFA before you usually end up having to rebuild the profile and clearing the credential manager.

When we opened the old, existing profile it didn’t ask for ANY authentication, it just started working. Modifying the Outlook profile by using the "Profiles" registry path is not supported and may cause your Outlook profile to be in an unsupported state. FixTechGuide support for Office 365 Serious problems might occur if you modify the registry incorrectly. Before you access it, back up the registry for restoration in case problems occur. We are looking at using conditional access policies where a user with a Domain joined PC is not prompted for MFA.

Outlook stuck in an MFA loop

Close and open your web browser again and go into Fix Outlook and Office365 Sync Issues SuiteFiles. You will most likely need to enter your Microsoft 365 credentials again so ensure you tick any box that says remember my credentials but it should now work for all future documents you open and not require your credentials. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. I regret that you are experiencing issues with your Microsoft installation.

Outlook 365 Password Prompt Issue on Windows Desktop

You can reply to reactivate the question if you decide you want to continue. Let's Outlook OST vs PST repair start by answering a few simple questions to understand the problem. We have been experiencing the exact same issue for months now. I experience the issue myself as well, every once in a while. On the off chance that none of these things solve this issue for you, please contact our support team at