After I tried to install SSL certificate to my VPS the httpd is down. I used this tutorial (BTW ln -s commando is not found, so I stopped here), but already renamed the .bak-files to their correct name again, as failed). Error: - Line 63 is not available on /000-sipconfig.vhost AH00548: NameVirtualHost has no effect and will be removed in the next release /etc/apache2/sit AH00526: Syntax error on line 63 of /etc/apache2/sites-enabled/000-ispconfig.vhost: SSLCertificateFile: file '/usr/local/ispconfig/interface/ssl/ispserver.crt' does not exist or is empty. Action 'configtest' failed. What should I do ? How can I undo or correct the error ? I'm on Ubuntu 16.04.