Recently, WD Backup gives an error when I am trying to initiate a backup - “Unable to backup files to My Passport. Please make sure your drive is connected and accessible.” However, the My Passport icon indicates that it is fine. Further, when I run the diagnostics from the WD Drive Utilities, it indicates that the drive is ok with a green check mark. Also, I can access all the files on the drive from Windows (10) File Explorer.
I have already been through the options suggested in the link that you provided. That link was already sent to me by WD Support. Unfortunately, it has not worked.
I have the exact same problem as RogerGB2. I know that my McAfee Virusware has just expired, and my laptop is being protected by my Windows 10 security now. Since the link you provided mentions virus security, I could use some more specific config instructions for how to allow the WD backup.