This message from the SCSI tape drive appears when Exabyte or DAT tapes generate too many soft (recoverable) errors. It is followed by the advisory Please, replace tape cartridge message. Soft errors are an indication that hard errors could soon occur, causing data corruption.
First, clean the tape head with a cleaning tape, as recommended by the manufacturer. If that remedy does not work, replace the tape cartridge. If the problem persists, you might need to replace the tape drive with new tape cartridges.