The problem was that Kcfinder adds a .htaccess file in your uploads directory. this htaccess file contains a line " Options -ExecCGI " that is not allowed in some hosts and causes an error preventing images from displaying
The solution is to prevent KCfinder from adding this .htacess file. This is easy by goiing to webassist/kcfinder/conf/config.php you will find this line :
'_check4htaccess' => true,
Change it to be false
I've done that for you and the page appears to be working now.