Hi. Sergio and welcome to the Magix VPX user to user forum.
Not sure what to say to you.
I've just tried the installer from the humble bundle site and it has all downloaded and now registered the Vegas Movie Studio. A few months ago I activated and now also use VPX.
Check your firewall and antivirus settings is all I can suggest at this point as the servers seem to be working as far as I can tell.