Microsoft add ins (excel, word etc) unable to add

Question

Hi, I’m hoping someone can help. I’ve spent all day on this today and just an hour and a half with a Microsoft employee remote logged in only to be told there is a known glitch with Microsoft that will be fixed, don’t know when. Any help would be appreciated I’m trying to add Claude but can’t even add any add ins.

Answer 1

This is currently a widely reported bug with Office add-ins since Saturday, many people are reporting the same problem, we need to wait for Microsoft to resolve the problem and provide a patch, the best option is to open the Feedback panel in an Office app and report this to their Office developers.

Answer 2

There are several current issues that can prevent installing or loading Office add-ins like Claude in Excel or Word. Some are service-side problems that Microsoft is already mitigating, and others are client-side configuration or policy issues.

Given that support has already said there is a known glitch, the most relevant current issues and actions are:

1. Possible store/update issue with Office Add-ins

• There is an active issue where Office Add-ins can fail to update or load correctly from the Store, which can make add-ins appear unavailable.
• Recommended actions while fixes roll out:
  1. Close all Office apps (Word, Excel, etc.).
  2. Reopen the app and try adding the add-in again.
  3. Ensure Microsoft 365 Apps are fully up to date.
  4. If it still fails, wait and retry later; the underlying delivery issue is being mitigated.

2. Tenant or policy configuration blocking add-ins

• If an ADD-IN INFORMATION bar appears at the top of the task pane with a message about configuration (for example, store add-ins being blocked), this is typically due to how add-ins are configured in the Microsoft 365 environment.
• In that case, the Microsoft 365 administrator must adjust add-in policies. End users cannot override these settings.

3. Known issues with add-ins not loading or appearing

• There are known issues where add-ins may fail to load, appear missing, or not deploy correctly due to Exchange authentication changes or client bugs.
• For centrally deployed or organization-scoped add-ins, Microsoft is rolling out mitigations; if problems persist, the guidance is to contact Microsoft Support with diagnostic information.

4. If the error is “Access Denied” when launching an add-in

• That specific issue (for add-ins relying on .NET Framework Office binaries) is fixed in newer Office builds.
• Running an Online Repair of Office and ensuring the build is current resolves that particular scenario.

If the environment is managed by an organization (work or school account), and other users can add add-ins but this account cannot, the admin may need to review add-in and store access policies for this specific user.

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References:

• Office Add-ins known issues
• Troubleshoot user errors with Office Add-ins
• "Access Denied" when launching an Office add-in
• View, manage, and install add-ins for Excel, PowerPoint, and Word