NOTE:

This article is for users where add-in store access is NOT being intentionally blocked, but when trying to load the add-in store, it continues to load indefinitely and/or the add-in store window displays a message saying that 'no add-ins were found'.


Summary

Organizations may encounter an issue where the AppSource Add-in Store fails to load within Microsoft Office desktop applications, despite functioning correctly in a web browser.

This issue typically:

  • Affects all users within a tenant
  • Persists across devices and networks
  • Occurs only within Office desktop applications

The most common cause is a disabled Microsoft-managed service principal required for Office authentication and embedded web functionality.


Important

This issue is caused by a tenant-level configuration in Microsoft 365 and cannot be resolved by individual users.

If you are an instructor, please forward this article to your institution’s Microsoft 365 / IT administrator. The steps below require administrative access to Microsoft Entra (Azure AD).

Quick Resolution

Have your Microsoft 365 administrator complete the following steps:

  1. Navigate to the Microsoft Entra Admin Center
    https://entra.microsoft.com
  2. Go to:
    • Applications → Enterprise applications → All applications
  3. Search for:
    • Microsoft Teams Services
  4. Open the application → select Properties
  5. Set:
    • Enabled for users to sign-in = Yes
  6. Save changes, wait a few minutes, then restart Office applications

Symptoms

One or more of the following behaviors may be observed:

  • “Get Add-ins” fails to open or loads a blank interface
  • AppSource works in a browser but not within Office applications
  • Office displays account-related warnings such as:
    • “There’s a problem with your account”
    • Unexpected or garbled authentication dialogs
  • The issue is consistent across multiple users and environments

Technical Explanation

Microsoft 365 desktop applications rely on a multi-resource authentication model built on Microsoft Entra ID (Azure AD). During sign-in, Office applications request access tokens for a collection of Microsoft-managed service principals that support core functionality.

These service principals include:

  • Office and Microsoft 365 core services
  • SharePoint Online and web application infrastructure
  • Additional Microsoft-managed services used in authentication and embedded experiences

If one or more of these required service principals are disabled, token acquisition may fail. In many cases, this does not result in a clear authentication error, but instead causes other service failures in features that depend on certain web content.

The AppSource Add-in Store is one of those features. Through Office, it uses an embedded web experience that is dependent on successful authentication across these services.

One commonly observed example is the Microsoft Teams Services principal. While organizations may not actively use Microsoft Teams, this service can still participate in shared authentication. If it is disabled:

  • Office may be unable to complete its authentication chain
  • Embedded web components (such as AppSource) may fail to initialize
  • Account-related warnings may appear in Office applications

It's important to note that this dependency is not always explicitly documented, and similar issues may arise if other Microsoft-managed service principals required for authentication are disabled.

Resolution (Detailed Steps)

1. Open Microsoft Entra Admin Center

https://entra.microsoft.com

2. Navigate to Enterprise Applications

  • Applications → Enterprise applications → All applications

3. Locate Relevant Microsoft Service Principals

Search for:

  • Microsoft Teams Services

If your organization has restricted or disabled Microsoft-managed applications, your administrator may also review other Microsoft-owned service principals to ensure they are not unintentionally disabled.

4. Enable Sign-In

  • Select the application
  • Open Properties
  • Set:
    • Enabled for users to sign-in = Yes
  • Click Save

5. Restart Office Applications

  • Close all Office applications
  • Reopen Excel, Word, or PowerPoint
  • Navigate to:
    • Insert → Get Add-ins

Expected Result

After enabling the required service principal(s):

  • The AppSource Add-in Store loads correctly within Office
  • Account-related warnings are resolved
  • Add-ins can be browsed and installed as expected

If You Are an Instructor

You will likely need assistance from your institution’s IT department.

When contacting them, you can provide the following summary:

We are unable to access the AppSource Add-in Store within Microsoft Office desktop applications.

This appears to be caused by a disabled Microsoft-managed service principal (commonly “Microsoft Teams Services”) in Microsoft Entra ID.

Please review Enterprise Applications and ensure required Microsoft service principals are enabled for sign-in.

Additional Considerations

  • Enabling a Microsoft-managed service principal does not require enabling or deploying the associated product (e.g., Microsoft Teams)
  • No changes to user licensing are required
  • These service principals often function as part of shared platform infrastructure rather than standalone applications

Troubleshooting

If the issue persists:

  • Allow several minutes for changes to propagate
  • Sign out and back into Office:
    • File → Account → Sign out → Sign in
  • Verify that the service principal remains enabled
  • Review other Microsoft-managed service principals that may have been disabled