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Troubleshooting: The “Add-In Could Not Be Started” Error in MS Outlook for Windows

If you have successfully installed the Add-In and on trying to open it in MS Outlook for Windows you get an error notification “ADD-IN ERROR. This add-in could not be started. Close this dialog to ignore the problem or click “Restart” to try again”, that is most probably caused by your MS Edge configuration (this browser’s engine is used to render Revenue Inbox Sidebar in MS Outlook for Windows).


Try the following solution:

1. Open the Internet Explorer browser (IE is installed by default in all Windows systems); in it, click the Tools (Gear) icon and select Internet Options


2. Open the Security tab, click the icon Internet

3. Select the Enable Protected Mode checkbox and click OK


4. Restart Internet Explorer and MS Outlook

5. Try opening the Add-In in MS Outlook

6. If the issue persists, also Enable Protected Mode for Restricted sites, restart IE and MS Outlook and try again


If that does not resolve the issue, contact our Support team for further assistance.