Workspace Reservations Outlook Add-in error: This browser is not supported in this experience or This add-in could not be started


After installing the Workspace Reservations Outlook Add-in, the Outlook Add-In might show this error:

Or you might see this:

Release or Environment



WebView2 runtime isn't installed on the client devices.

As stated in the documentation: Install Workplace Reservations for Microsoft Outlook Add-in

If you are installing Workplace Reservations for Microsoft Outlook Add-in application in a Windows system, it is required to have the “WebView2 runtime” installed on the client devices. You can downloaded tit here:


Install WebView2 on the client devices. You may need to contact Microsoft Support for assistance with this.

Here's the Microsoft documentation with a compatibility matrix for Browser used by Office Add-ins

Take note also of the footnotes, especially footnote 4:

On Windows versions prior to Windows 11, the WebView2 control must be installed so that Office can embed it. It's installed with Microsoft 365, version 2101 or later, and with one-time purchase Office 2021 or later; but it isn't automatically installed with Microsoft Edge. If you have an earlier version of Microsoft 365 or one-time purchase Office, use the instructions for installing the control at Microsoft Edge WebView2 / Embed web content ... with Microsoft Edge WebView2. On Microsoft 365 builds before 16.0.14326.xxxxx, you must also create the registry key HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\WEF\Win32WebView2 and set its value to dword:00000001.