Yeah, cbt reset with
cd C:\Program files\UrBackup
urbctclt reset x:
may help. Can you also investigate if only MFT!=MFTMirr is the problem? Use losetup --offset=$((512*1024)) to setup the volume. Then use ntfsfix to fix the NTFS error.
If this is something the naturally occurs, there is already code in UrBackup to fix it…