The most common cause of this is that the name you have given to the tracker contains a symbol or punctuation mark.
The name given can only be letters or numbers, it can include a space.
Double check the that you have the correct device number. You can get the device number from scanning the QR code, writing the numbers from within the code or copying the numbers written inside your guide book.
Our helpful 'Set Up' team will test that your tracker is working and write down your device number before sending it out.