Why is the PVT app not accepting my serial number?

Each serial number is device-specific and consists of 8 characters.  This serial number will either be represented by all letters or combination of letters and numbers.  Registering a serial number within the wrong app will result in an "invalid serial number" error message.  Please check that you have downloaded the correct app for your device. 

The PVT app icon looks like this:

Please note: when entering the serial number, do not include "SN:".