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

• FYI outlook 2013 requires a registry setting to work with MA.
• I have a valid MS 365 subscription that includes 5 device licenses.
• 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.
• Serious problems might occur if you modify the registry incorrectly.
• Have looked all over and people have all sorts of possible solutions, but nothing we found to resolve the issue and get a new issue daily and just keep going through until it eventually works.
• The user had Office 2015 and Office 2016 credentials and Teams credentials that we deleted.

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. Outlook stuck updating folders solution 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 Outlook profile repair and recovery steps 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

So not doing anything at all even seems to work. Which to me sounds recreate Outlook profile step by step like the issue is service side, not client side. Problem doesn’t just happen on PC’s connected to the internal network, but can happen when a laptop is remote and connected via external wifi or mobile hotspot.