Why won't the barcode scanner work?

On iOS 7, Deliveries uses Apple’s new barcode scanner. In most cases it works perfectly and is even faster than before. However there are certain barcodes it can’t scan, particularly ones from DHL Germany and Hermes. If you have Delivery Status 5 installed, you can press and hold on the barcode button for an option to choose the old ZBar scanner. Once you’ve selected it your preference is remembered for you, so you can just tap the button normally in the future. iOS 8 supports more types of barcodes, so you won’t need to switch.