I've installed the application and send an email to the address listed in the installation window.
Here is the one I've received:
"Thanks to using the PLMPack platform, the eco-design software to optimize packaging systems.
The installation key for your free software license is:
StackBuilder 2: FX15VR70ZH07
PLMPackLiB 8 : FX16VR80ZH08"
I installed the product and it works just fine.
Always download the latest version from the following link: https://stackbuilder.codeplex.com/