If you are getting the message “Apache restart failed. Unable to load pid from pid file and no httpd process found in process list.” It may cause by the problem with mod_ssl.
Just check the log files using tail -f /usr/local/apache/logs/error_log

If you are getting “File exists: Cannot create SSLMutex with file `/usr/local/apache/logs/ssl_mutex’Configuration Failed“Also check apache status :

[root@vps12105 ~]# service httpd status

Looking up localhostMaking HTTP connection to localhost

Alert!: Unable to connect to remote host.
lynx: Can’t access startfile http://localhost/whm-server-status

Resolution :

Rename the file /usr/local/apache/logs/ssl_mutex to /usr/local/apache/logs/ssl_mutex_bkand try restarting the apache.

Steps :

mv /usr/local/apache/logs/ssl_mutex /usr/local/apache/logs/ssl_mutex_bk

service httpd stop

service httpd startssl

service httpd status