Why is Backup Exec failing to communicate with my tape library?

Version 1

    Cause: If VERITAS Backup Exec is failing to communicate with the library (for example, a media-dismount operation fails), it might be because there is a problem with the association between the tape drive and the tape library, or it might be because there is an issue with SCSI connectivity.

    Solution:
    1. In the Microsoft Windows Device Manager, do the following:
    a. Verify that the Medium Changer and Tape Drive devices can be seen.
    b. Verify that the driver for the Medium Changer is "Unknown Medium Changer" and that Tape Drives are using VERITAS drivers
    IMPORTANT: If the devices cannot be seen, you might have an issue with SCSI connectivity. Check your SCSI connections and contact technical support if you continue to experience problems.
    2. In Backup Exec, do the following:
    a. On the Device tab, disable and re-enable the tape drive.
    b. Run the Device Configuration wizard, and disassociate the tape drive from the tape library by dragging the tape drive down to the Stand Alone section of the Device Configuration window.
    c. Run the Device Configuration wizard again, and re-associate the tape drive with the tape library by dragging the tape drive from the Stand Alone section to the Library.
    d. Finish the wizard process.