in ISPConfig 3 control panel, Website basedir is /var/www. setup site-1.com (its document root is /var/www/site-1.com/web) and site-2.com (its document root is /var/www/site-2.com/web) sites. install the shared drupal codebase in /var/www and the drupal site installation is fine, but after installation, when browsing to http://localhost, there is a prompt pop up with the below message (browser is firefox): You have chosen to open which is a: ~ file from http://localhost What should Firefox do with this fine? Open with (radio button) Save File (radio button) Do this automatically for files like this from now on. (check box) why that? how to fix it? Before I tried to install the shared drupal code base in the domain directory, e.g. /var/www/site-1.com/web, after installation, the browsing to http://www.site-1.com is fine. what is the difference between the above two installation? apache conf files, vhost file, setup in ISPConfig 3 control panel or ...... ?