For Microsoft Office 365 in Windows 10
I was running Microsoft Office 365 with Windows 10 and tried the mentioned solutions to remove the registry key without success.
I went to Settings -> Apps in an attempt to repair the Office 365 suite:

To get there you can follow these steps:
- Open Start
- Select Settings
- Select Apps
- In the default page, Apps & features, search for Microsoft 365
- Select “Microsoft 365”
- Select “Modify”
I selected the Quick Repair option:

This resolved the issue for me.