Suddenly, I am having a problem backing up my C drive to my external drive. It starts without incident and backs up. After about 90 minutes, I receive the following notification errors Error EC8F17B7: Cannot create recovery points for job: Complete System Backup.
-Error E7C3000F: Device \.\SymantecSnapshot0 cannot read 4104 sectors starting at LBA 171370320.
–Error EBAB03F1: Data error (cyclic redundancy check). Everything that was in my Norton backup folder disappears and the fold is empty.