HTTP 500 Internal Server Error
The 500 Internal Server Error page signalises an unspecified server-side error. Unfortunately, it is also the most generic 5xx status code, and sometimes, it is difficult to determine the cause.
There are several reasons why an HTTP 500 message appears. For example, the problem could be server downtime due to physical damage, a power outage, or a server overload due to requests during a DDoS attack.
However, despite the name, the 500 status code does not necessarily refer to a problem only on the server. It could also be a bad setup, incompatibility of PHP versions, or a misconfiguration of the .htaccess file.