Hi Danilo,
Our quickstart is standard Akeeba - there is nothing different in our install from any other Akeeba install so you need to go to their site for their extensive troubleshooting pages.
but generally it is not enough disk space on your server, wrongly configured permissions on your server etc etc
You need to look at the install to see if all files are successfully there on the server , that the database is populated and find exactly what that error is - ask your host for example - that's what they are there for
also whay do u send me this link?
www.domain.it/installation/index.php
you can't have the installation folder still there after a successful instal!!
Cheers