Barcode is not recognized

The scanner is set up for barcode recognition in a format that does not match the actual barcode type.

Even if your scanner is capable of recognizing barcodes in multiple formats, it might be programmatically limited to recognizing only one format at a time. Refer to documentation that comes with the scanner for details on how to specify a barcode format that matches your barcode format.

Barcode parameters were changed, which made the configuration of the scanner obsolete.

Adjust your scanner to recognize new barcodes.

The scanner was replaced due to hardware failure.

Configure the new scanner to recognize the desired barcode format. Refer to documentation that comes with the scanner.

The scanner's configuration became corrupt due to improper shutdown.

Restore the scanner's configuration either manually or from a backup file, if available.

The surface you are scanning the barcode from has a shiny, reflective appearance—for example, like plastic or metals.

Remove the plastic cover.

The barcode is unreadable.

Check the barcode visually. Try recognizing it with another scanner to check whether it is readable.