The library barcode reader is unable to read the label of a tape cartridge. The cartridge is found in the slot with the given element number.
When LABELSOURCE=BARCODE is specified on the LABEL LIBVOLUME command, volumes without a barcode cannot be labeled. When the VOLRANGE or VOLLIST option is specified on the CHECKIN LIBVOLUME command, volumes without a barcode cannot be checked in.
Examine the cartridge to ensure it has a barcode label and that it is compatible with the barcode reader. Not all vendors' labels are readable by all libraries. Check that the barcode reader is configured and is functioning properly, if necessary.