Backups with HP Data Protector may fail with the following error:

REQUEST SENSE call failed. Possible cleanme signal detection failure

First, attempt to perform a manual clean of the drive, then try re-running the backup. If it fails again, power-cycle/reboot the drive/library.

If the error still persists, start HP Library and Tape Tools and run a drive assessment. You'll need to load a tape into the drive first. If the test fails (i.e. it returns an error code, such as internal error), call HP for support.