RapidSearch Pro 2.5.1 demo: config.php missing

Hi!
I installed the demo version of RSP 2.5.1.
When I try to access the admin dashboard, I receive these messages:

Warning: require(config.php): failed to open stream: No such file or directory in /web/htdocs/[…]/rw/cerca/files/rspro/index.php on line 11

Warning: require(config.php): failed to open stream: No such file or directory in /web/htdocs/[…]/rw/cerca/files/rspro/index.php on line 11

Fatal error: require(): Failed opening required ‘config.php’ (include_path=’/web/htdocs/[…]/rw/cerca/files/rspro:.:/php5.6/lib/php/’) in /web/htdocs/[…]/rw/cerca/files/rspro/index.php on line 11

I noticed that index.php in …/files/rspro/ server directory need a config.php file that is missing in the directory it is in.
I think (maybe I’m wrong) that config.php is the file in which the RSP stack save the parameters to access the database…
What happened?