A command is issued with the CHECKLABEL=BARCODE option. The library is unable to detect that the cartridges have valid barcode labels. The barcode reader is disabled or it is unable to read the labels.
Unless the command is checking in cleaning cartridges, the process continues by loading the cartridges into the library's drives and reading the label from the tape. Cleaning cartridges have no internal label that can be checked by loading it in the drive.
Cancel the process if you do not want to load all of the cartridges into the library's drives. Examine the cartridges to ensure they have barcode labels and they are compatible with the barcode reader. Not all vendors' labels are readable by all libraries. Check that the barcode reader is configured and functioning properly, if necessary.