Claude Add-in Error in Excel

Hi Microsoft Community,

I'm having an issue with the Claude for Microsoft 365 add-in in Excel for Mac.

Environment:

Mac

Microsoft Excel desktop for Mac

Personal Microsoft account (not a work or school account)

Claude for Microsoft 365 add-in

Excel for the web

Issue:

When I try to add or use Claude in the Excel desktop app for Mac, I receive this error:

“Add-in Error: You don't have permission to use this add-in. Contact your system administrator to request access.”

The important point is that I am using a personal Microsoft account, so there is no organizational administrator managing the account.

What I've confirmed:

The Claude add-in works successfully in Excel for the web using the same Microsoft account.

The problem occurs specifically in the Excel desktop application on Mac.

This appears to point to an issue with the Mac Office client, add-in authorization, or the Office add-in catalog rather than my Claude account or Microsoft account permissions.

I've already tried closing and reopening Excel, but the permission error remains.

Has anyone encountered this with Claude for Microsoft 365, or with other Office add-ins, on Excel for Mac?

In particular, is there a known issue with personal Microsoft accounts and Office add-ins on the Mac desktop client? Is there a way to reset the add-in/account authorization without reinstalling Office?

Thanks.