How Can You Instantly Resolve Outlook’s [4usqa] Error? Proven Solutions for a Critical Problem

Why Is Outlook Failing With Error [4usqa]? Discover the Powerful Fix for This Frustrating Issue

Microsoft Outlook users have recently encountered a disruptive error-[4usqa]-that prevents access to emails and business communications. This issue, which began surfacing around May 8, 2025, has affected countless organizations and individuals relying on Outlook for daily operations.

What Is the [4usqa] Error in Outlook?

When launching Outlook, users receive an error dialog stating:

“Something went wrong. [4usqa]”

The error blocks access to emails in the Outlook desktop app and, in some cases, on mobile devices. The web version of Outlook (outlook.office.com) remains unaffected, allowing continued email access via browsers.

Root Cause: Microsoft Information Protection API Disabled

The primary cause of the [4usqa] error is the deactivation of the Microsoft Information Protection API within Microsoft 365 tenants. This API is essential for authentication and security services in Outlook. When disabled, users cannot sign in, triggering error codes such as [4usqa] and sometimes CAA2000B.

Why Was the API Disabled?

Microsoft appears to have made backend changes, possibly related to licensing updates or the recent shutdown of Skype for Business. Some speculate that the deactivation is linked to the transition from Skype to Microsoft Teams or changes in Office 2021 licensing.

How to Fix the [4usqa] Error: Step-by-Step Guide for Administrators

To restore Outlook functionality, administrators must reactivate the Microsoft Information Protection API:

1. Sign in to tenant’s Microsoft Entra Admin Center
2. Go to “Enterprise Applications” in the left sidebar.
3. Under “All applications,” select the “Hidden apps” filter.
4. Look for the application with ID: 40775b29-2688-46b6-a3b5-b256bd04df9f or search for “Microsoft Information Protection API”.
5. Open the API’s properties.
6. Set “Users can log in” to Yes.
7. Apply and save your settings. The fix is typically immediate.

Additional Troubleshooting Steps for Users

If the API fix is not possible or does not resolve the issue, try these user-level solutions:

1. Use Control Panel > Programs and Features > Microsoft Office > Change > Repair.
2. In Mail settings, add a new profile and set it as default.
3. Download and run the Microsoft Support and Recovery Assistant (SaRA) tool to diagnose and fix Outlook issues.
4. Uninstall and then reinstall Microsoft Office, ensuring you use the same Microsoft account for activation.

Key Points to Remember

• The [4usqa] error is a result of a disabled authentication API in Microsoft 365.
• Only administrators can resolve the root cause by re-enabling the Microsoft Information Protection API.
• End users can attempt profile recreation or Office repair, but these are temporary or partial solutions.
• The issue is under investigation by Microsoft, and updates may be provided via the Microsoft 365 Service Health Dashboard (EX1072812).

By following these clear steps, you can quickly restore Outlook’s functionality and minimize business disruption. Administrators who promptly address the API setting are seeing immediate, positive results, allowing teams to return to productive work without delay. If you’re struggling with this issue, know that you are not alone-many organizations are facing the same challenge, and these proven solutions are helping users worldwide regain access to their critical communications.