Symptom

Scanning a book displays an error message stating "Invalid length. Expecting 16 digits, got 13."

Cause

A scanning setting has changed, usually after a clean boot or a dead battery. From what we can tell, there's no logical explanation why it changed.

Resolution

Scan this barcode to correct the setting.

You can scan from anywhere. You don't need to go to a particular place to scan. Just scan it.