Hey there, Emanuele Boccaletti
The error message suggests that an error occurred when you tried signing up for the Azure free account.
Please can you try clearing your cache and cookies for your browser and try and sign up for the Azure Free account again through this link: https://go.microsoft.com/fwlink/?linkid=2227353&clcid=0x409&l=en-us
Hope this helps,
Nathan