502 Bad Gateway nginx
That means that most likely your Apache service is down or is experiencing problems. We recommend that you login to your service via SSH and investigate further. You can check if your Apache service is up also if you are using cPanel/WHM, and if necessary restart it through the Services section of cPanel/WHM.
You can restart Apache through ssh / command line interface via the command:
service httpd restart
We recommend that you review your Apache error_log, monitor for any errors that the restart command may return, any service load, logs, running processes, etc.
Please, note that you may run into this issue also if there is a configuration issue with your Apache config file, and the web process is unable to start due to this.
If you are experiencing this issue frequently. If you need further assistance please, contact our support.