We couldn't connect to the '{0}' catalog server for this add-on.

Question

I keep getting an error message when trying to add add-ins. This is true for all add-ins I've tried in the browser version of Word and Excel, although sometimes I get the error message and the randomly selected add-in appears anyway. In the desktop version I'm not even able to search for add-ins, there's is just a link to the Microsoft store and the add-in I need doesn't show up in the search.

I'm using a Mac with a Personal Microsoft account. I've already tried all of the things mentioned online to resolve the issue but nothing has worked. Any guidance would be appreciated.

Answer 1

Hello Christy

From what you described, you’re having trouble adding Office add-ins on both Word/Excel for the web and Office for Mac, and you’re seeing a “couldn’t connect to the catalog server” error message.

First, please make sure Office for Mac is fully updated, then restart your Mac and test again. Sometimes add-in/store issues can be related to an older Office build or a temporary Office service/cache state.

After that, open Word or Excel and go to Word/Excel > Preferences/Settings > Privacy, then make sure Turn on all connected experiences under Manage Connected Experience is checked. If it is already enabled, try turning it off, restarting Office, then turning it back on and restarting again.

For the browser version, I’d also suggest testing with Edge or Chrome, allowing third-party cookies, disabling ad blockers/tracking extensions temporarily, and trying a different network or mobile hotspot. You can also try installing the add-in directly from Microsoft AppSource, then reopen Word/Excel and check Insert > Add-ins > My Add-ins.

Hope this could help. Please let me know how it goes on your side!

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Answer 2

The error "We couldn't connect to the '{0}' catalog server for this add-on" indicates a problem reaching the add-in catalog, not a problem with a specific add-in.

From the available information, this error is documented in SharePoint/Excel Web App scenarios where the catalog URL or access path is incorrect, or where the user does not have access to the catalog that hosts the app. In those cases:

• The error appears when opening or using an app/add-in because the catalog server cannot be reached.
• Causes include an incorrect catalog URL or the user not having permission to the catalog.
• Resolutions in those environments involve correcting the catalog configuration or publishing the app to a store that the user can access.

In a personal Microsoft 365 scenario on Mac, this typically means the environment cannot properly reach or use the catalog that should supply Office Add-ins. Since the issue affects all add-ins in the browser versions and the desktop client is not showing the expected add-ins, the problem is with how the catalog or store is being reached, not with individual add-ins.

Because catalog connectivity and configuration are controlled on the service side, and the documented fixes in the provided material are specific to SharePoint/Office Web Apps Server 2013 and organizational app catalogs, the next step is to work with Microsoft support so they can verify catalog access and store configuration for the account and tenant.

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References:

• "We couldn't connect to the catalog server for this app" error when you use Excel Web App to open a spreadsheet
• "Couldn't connect to the catalog server for this app" error when you click a guest link to a SharePoint Online item
• Troubleshoot user errors with Office Add-ins
• Errors when Office add-ins start
• Office Add-ins known issues