We've configured Virtualmin to create virtual servers in Apache mod_php mode. Strange enough that after a virtual server is created it shows WSOD in browser. However, switching the "PHP script execution mode" option to FCGId mode starts showing the website correctly. Switching back to "Apache mod_php" shows website normally. But we really can not be switching to FCGId to only switch back to Apache mod_php constantly.
WSOD when a virtual server is created in Apache mod_php mode