Please read:

If you are using a version below 5.32 please re-download the newest version here.
Version 5.32 or higher got a new automated key emailer included (Registration Dialog). Note: You don't have to pay again if you are a registered user. Just use your known username (see Shareit Order Confirmation EMail).

The system will check if your exist and sent the new key to your email adress.

This will help you to get a new key if needed immediately.