Error: "Please upgrade your browser to use Grammarly"

The error message “Please upgrade your browser to use Grammarly” in Grammarly for Microsoft Office looks like this: 

To resolve this issue, please follow these instructions:

1. Download and run this file: https://grammarly-support-static.s3.amazonaws.com/force_oauth_PerUser.reg 
2. Afterward, please restart MS Word or MS Outlook.
3. Then, go to MS Word or MS Outlook, and click Log in. Please enter your login credentials or click Continue to Grammarly in the window that opens next.
4. Please check if you are logged in to Grammarly for MS Office.