I tried to translate from Italian the field "Genitore" > "PAGINA BASE" with "Parents" > "BASE PAGE", but probably is not the correct translation... "PAGINA BASE" will be probably the HOME PAGE...
I try to summerize my problem in other way.
Here the is the home page I want to view in the website: http://goo.gl/Gi76NC
Here you can see a screenshot of the home page when I try to create another page (now I have only AZIENDA, REALIZZAZIONI and CONTATTI in home page). The custom home page disappear!
The example page created is "Test page that causes error":
Only deleting the page just created I can overcome the problem and the cust HOME PAGE appear (sorry but I can't leave the problem online...)