UPDATE: I changed the server and the problem is the same.
so it is not .htaccess, not server misconfiguration.
the problem is some misconfiguration on the db.
but which one? :-(
"Destiny is not a matter of chance, it's a matter of choice"
I would first try these config settings:
site_start is published?
maybe try an other ID for site start and unauthorized page
what kind of plugins do you use, maybe 1 by 1 disable them and check result?
did it happen after updating yams? are the correct settings still checked? OnPageNotFound etc.
any error messages in report?
check for hacks, weird .php files
you could try recover database tables in phpmyadmin.
good luck
Evolution user, I like the back-end speed and simplicity

found the problem!!!!!!: it was the validation of headers HTTP_REFERER
Putting it off everything goes right!!
Many thx to all!
"Destiny is not a matter of chance, it's a matter of choice"
it was a mistake. the problem is still open.
:-(
in summary:
- The friendly url not working (if i disable Friendly URL the website go right)
- in this server i have another website with modx 1.0.15 and friendly URL ok (www.industria-alimentare.com)
- .htaccess is correct
- I tried disabling all plugins, one at a time, but the problem remains
- I tried to edit pages d 'error and start but the problem remains
I do not know what to look, help me!!!
:-(
"Destiny is not a matter of chance, it's a matter of choice"