Unable to find file HRESULT: 0x80070002 error when enabling a backup

I have one computer with this issue and only on one drive on that computer. WD Support believes it is a .NET issue however, why only on the C: drive? I have 4 other computers running WIN10 with no issues. Need help!

10 down vote accepted I finally figured out the problem. The hidden system reserved partition contains boot configuration data (BCD). Unfortunately, this partition was offline and so was inaccessible. This caused Windows Backup to fail with the symptoms I originally described. However, other parts of Windows are affected, too.
CCleaner Happy Wheels VLC

The disk.EnableUUID parameter of the VM must be enabled. VMs created on 4.1 or later have this parameter enabled by default. The following configurations are performed automatically by backup job to avoid data inconsistency and perform application-consistent backup. If vidmate backup job cannot enable disk.EnableUUID due to some reasons, configure the parameter manually using the following procedure,. :blush: