How you can upgrade an existing license.

Load your existing license from a different platform to obtain your personal discount code. You see an error message, that you can't use that license: 

The system now retrieves your personal discount code in the background. The "buy a license" link changes and shows your personal discount information. 

Click on that link to buy a license with discount! 

This feature requires version 1.5.4 or later. 

You can only buy one license with a discount. After a purchase your personal discount code is used up.

Buying a license 

Activating your license file

Licensing Lights-Out