Форуми / Cotonti / Support / Config change and site doesn't work

Hello everybody,

I changed a value (cache true) in the config.php and since then my Cotonti Genoa 0.6.20 site doesn't work anymore. The browser says I need install.php

How can I get the site back without restarting from install.php?

Added 41 minutes later:

OK, since the database was not populated yet, I deleted it, uploaded install, went through the install procedure and got my site back.

My question is - cannot I change anything in config.php and upload it after the site is installed? Shall I do any operation only through the administration panel?