Installation error in php script

Hi altervista!
I have found error in Free altervista hosting, i've uploaded an script in my altervista account (http://pjb.altervista.org) when i try to install that script (php script) as (pjb.altervista.org/install) it give error that

"configuration file not found"

this will come if configuration file does not exists, but actually it's exists, i have installed that script in other free hostings and it's working fine, what should i do to install that script on altervista hosting ?
In short!
Script is working on all free hostings instead of altervista

Which script are you trying to install?