Possible to avoid “Add-in Blocked Untrusted web add-ins from the Internet are blocked by default”

2
votes

Users are getting an error message when opening Excel workbooks that have a web add-in manifest pre-inserted into them, instead of getting prompted to trust the add-in.

Message: "ADD-IN BLOCKED Untrusted web add-ins from the Internet are blocked by default. This add-in is from \\myhost.us.mycompany.com\web-addins."

Environment:

  • Windows, Excel 2016 desktop.
  • Our web add-in (fka Office add-in) is hosted on a non-MSFT server.
  • The catalog location hosting the manifest is on a Windows file share. Call it \\myhost.us.mycompany.com\web-addins.

Research:

  • Googling for the first sentence in the error message returns 0 hits.
  • Looked for a setting in Excel > File > Options > Trust Center > Trust Center Settings > Trusted Add-in Catalogs. Nothing found to override this blocking behavior.

Question: Is there a way to avoid this message, other than adding the trusted catalog setting to every end-user's Excel configuration?

2
ms-officeoffice-addinsoffice-js

2 Answers

4
votes

To configure trusted catalogs automatically across an organization, you can set group policy using use the Office Customization Tool and the Office Administrative Templates.

The settings for this feature can be found at: Microsoft Office 2016 > Security Settings > Trust Center > Trusted Catalogs. We also support these settings for Office 2013.

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The 3 relevant template settings to enable are:

  • Allow Unsecure web add-ins and Catalogs
  • Trusted Catalog Location #1
  • Default Shared Folder Location

And here's an example for how you would complete the Default Shared Folder Location setting:

enter image description here

And as Philip's answer explains, deployment via a network share is not the recommended solution, but you can still use my instructions above if there's some reason why you want to deploy it this way.

1
votes

The general way to make apps available within your business is to publish them to an internal App Catalog, more information can be found here - https://dev.office.com/docs/add-ins/publish/publish-task-pane-and-content-add-ins-to-an-add-in-catalog and https://technet.microsoft.com/en-us/library/jj219429.aspx

If you want to publish them via a network share, then yes you would have to push out this setting to each end user individually.