Cause 1: The scanner was not set up to read this type of barcode symbology, or the bar code is damaged, covered up, or of poor quality.
Scan another bar code on a similar item. If it scans, clean the bar code giving you trouble. If you are still unable to scan, restore the scanner to original settings. If you still fail, try using other scanner.
Cause 2: The scanner does not recognize the programming bar code scanned.
Make sure you are scanning the correct programming bar code and try again.