SAP Knowledge Base Article - Public

3128552 - "ADD-IN ERROR" Message In C4C Outlook Server Side Add-In


You configured the Groupware Outlook server side integration and installed the add-in from Groupware Settings. However when in Outlook the add-in appears disabled (greyed out) and also the following error message appears:

"ADD-IN ERROR This Add-In could not be started. Close this dialog to ignore the problem or click "Restart" to try again."



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Reproducing the Issue

  1. Access your Microsoft Outlook.
  2. Add-In will be disabled and error will show up on side pane.


The issue is caused by Microsoft Edge Webview runtime software and can affect any add-ins (also third parties).


Engage your Microsoft Office support to follow the steps below:

1. Close Microsoft Outlook.
2. Close Microsoft Edge browser windows, if any are opened.
3. Download MS Edge Webview2 runtime from this location:

If this package does not work in your configuration, install an alternative version.

Browse this Microsoft resource: for versions compatible with different Microsoft Edge builds and x86, x64, or arm64 architecture.

4. Open your Downloads folder and install Webview2 on your Windows system. 
5. Launch Microsoft Outlook and check if Add-In can be opened and key sidebar controls are clickable.

See Also

The runtime’s security and stability are guaranteed by Microsoft, see this article for complete information on Webview2:


Groupware; Server side; Outlook; Integration; E-mail; Email; Add-in; Addin; Add-on; Addon; Side Pane; Side Panel; Error; Message; , KBA , LOD-CRM-GW-SCC , Invisible CRM - Smart Cloud Connect Solution , How To


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