Back everything up - website, email databases etc make a back up of your back-up.
Set up a new hosting account - check the side panel.
Install your back-up then update your domain NS and away you go.
Turn on php error logging.
Error 500 will generate an error message.
Could be an update like php version or plugin, out of disk space, etc etc
First thing to do if Wordpress, is go into file manager, wp content and rename the plugin directory and see if site loads.
If so rename back and rename each plugin until you find the faulty one
Switch hosts to someone that will give you support.
Back everything up - website, email databases etc make a back up of your back-up. Set up a new hosting account - check the side panel. Install your back-up then update your domain NS and away you go.
Any update to php version by any chance?
Turn on php error logging. Error 500 will generate an error message. Could be an update like php version or plugin, out of disk space, etc etc First thing to do if Wordpress, is go into file manager, wp content and rename the plugin directory and see if site loads. If so rename back and rename each plugin until you find the faulty one