Portions of FILENAME cannot be read. The backed up data is corrupt or incomplete. This file will not restore correctly.
I would receive this error numerous times in my ntbackup log.
In my case the C: drive would backup without any issue, but the D: drive would show these errors for every file in use.
My backup destination was a 2TB USB disk (G:) with a newer cluster size that is greater than 512. This is not really an issue for storing the backups. But somehow my shadow copy settings on the D: drive were using the G: backup drive as the place to store the shadow copies for the D: drive. And storing shadow copies on a drive with cluster size != 512 will fail. Note: on the G: drive itself shadow copies are disabled. Not needed for backup drive and will fail anyways because of above mentioned reason.