The library barcode reader is unable to read the label of a cartridge that is checked in as a cleaner. The cartridge is found in the slot with the given element number.
The cartridge is not checked in. If the library is being searched, the checkin process continues with the next volume.
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. The cleaner cartridge can be checked in without use of the barcode label by issuing the CHECKIN LIBVOL command.