Microsoft 365 Error Codes

How to Fix Microsoft 365 Sign-In Redirect Loop on Mac

Emma Brown Oct 14, 2026 869 views

Question details

The user is experiencing a continuous sign-in redirect loop when attempting to log into Microsoft 365 on a Mac, often triggering error AADSTS50196.

How to Fix Microsoft 365 Sign-In Redirect Loops on Mac

Product: Microsoft 365 for Mac
Device & OS: macOS
Scenario: Activating or signing into Microsoft 365 desktop applications using an organizational or school account.
Observed behavior: The login prompt loops repeatedly, the server terminates the client request, and the application fails to authenticate or activate the Office suite.

Before you start

Before proceeding with technical fixes, contact your IT administrator to confirm that your organization's policies permit signing in on multiple devices and that your account possesses an active Microsoft 365 license for Mac.

Solution 1Recommended

Remove Office License Files Using the Official Tool

Clearing corrupted license files is the most effective way to break the sign-in loop and reset the Microsoft 365 activation state.

Often, previous activation attempts leave behind corrupted or conflicting license files on macOS. Microsoft provides a dedicated tool to safely strip these files so you can start fresh.

Download the License Removal Tool

Navigate to the official Microsoft Support website and download the Microsoft license removal tool for Mac.

Run the Installer

Open the downloaded .pkg file from your Mac's Downloads folder and follow the on-screen prompts to complete the installation.

Restart and Sign In

Once the tool finishes removing the license files, restart your Mac. Open Microsoft Word or Excel and attempt to sign in again with your organizational account.

Remove Office License Files Using the Official Tool

Tool Completion: Running this tool only removes the activation licenses. It does not delete your Office applications or any of your personal documents.

Solution 2

Delete Office Credentials in Keychain Access

Use this method if the license removal tool fails, as outdated or corrupted Keychain passwords can force a redirect loop.

Solution 3

Clear Cached Office Data in Group Containers

Deleting the Group Containers cache removes stubborn background data that might be triggering the AADSTS50196 error.

Free Microsoft Office alternative

Try WPS Office: A Hassle-Free Alternative for Mac

If Microsoft 365 continues to block your workflow with complex activation errors or sign-in loops, consider switching to WPS Office. It provides a lightweight, highly compatible, and free office suite that works seamlessly on macOS without strict organizational login requirements.

1. Download the Installer: Visit the WPS Office website and download the Mac version.
2. Install WPS Office: Open the downloaded file and drag the WPS Office icon into your Applications folder.
3. Start Creating: Launch WPS Office and immediately begin working on your documents without complex sign-in barriers.

Fully compatible with Microsoft Word, Excel, and PowerPoint formats.No frustrating sign-in loops or complex enterprise activation requirements.Lightweight software that runs smoothly on macOS.Free to download and use with a highly familiar user interface.

microsoft office alternative - wps office

Frequently Asked Questions

What does error AADSTS50196 mean on Mac?

Error AADSTS50196 indicates that the Microsoft authentication server terminated a repeated client request. This usually happens when corrupted local credentials or cached files force your Mac into a continuous sign-in redirect loop.

Will deleting the UBF8T346G9.Office folder delete my documents?

No. The UBF8T346G9.Office folder only contains Office cache, application settings, and license data. Deleting it will not affect your locally saved personal documents, though it may reset custom application preferences and Outlook profiles.

Why does my organization block my Mac from activating Office?

Many organizations implement Conditional Access policies. These security measures can restrict logins to managed company devices, require connection via a corporate VPN, or limit the total number of devices you can use to activate Microsoft 365.

Microsoft Office Error Codes