I had my LAMP server crushed for some reason. That's why I've completely removed it and installed once again. Installation was successful and "localhost" is working fine. However every time I'm trying to add a virtual host (using a2ensite command) my apache2 server stop working. When I run a2dissite command of a corresponding virtual host, the server start working again. Please, help me to solve this issue.
As of for subdomains 000-default use: