I have previously made changes and therefore have the GSX folder in %appdata, the last change that worked was on 11/21/2017 12:21PM (taken from the GSX folder)
This clearly indicates that something in your system has changed after that date, which is not preventing that folder from being written. The most common issue is the antivirus and even if it's now disabled/excluded, it might even have changed the permission on that folder.
Or, you might have changed your user account, so that folder cannot be written under a new user.
Try this:
- Copy the whole GSX folder under %APPDATA% to a safe place.
- Remove it
- Reinstall GSX
- Restore just the files there.