If you receive the mentioned Add-in error please follow the steps given below to resolve the issue.
Even thought your default browser is not Internet Explorer this article could apply as Microsoft leverages Internet Explorer for users on older versions of Windows.
Enable Protected Mode in the Internet Properties
- Close Outlook and all your browsers.
- Open Internet Explorer.
- Click Tools.
- Click Internet Options.
Alternatively, for steps 2 to 4; you may also access the Internet Properties through the steps below:
- Press 'Windows logo' key + R on your keyboard.
- Enter inetcpl.cpl ten press Enter key.
- Click Security tab.
- Select Internet Sites zone.
- Select Enable Protected Mode (make sure box is checked).
- Click OK.
- Restart Internet Explorer and Outlook.
- Try to reproduce the issue