CST - Error while checking certificate

I just installed CST Studio Learning edition, and when I open the program, I get  "Error while checking certificate". I had a commercial version on my computer, but I did a full removal (uninstall and then clear data in register, appData and Program Files) prior to the installation of the learning version. The installation never asked me to generate a license with my email. 

Thanks!

CST Studio Suite ​​​​​​​