HTTP status codes / 5xx — Server error
500 Internal Server Error
What it means
Something broke inside the server — an unhandled exception, a crashed handler — and it has nothing more specific to say.
What causes it
Application bugs, unhandled edge cases in input, dependency failures (database down), misconfiguration, out-of-memory kills.
How to fix it
As a user: retry later; it is not your fault. As the operator: the real error is in your server logs and error tracker — 500 is only the wrapper. Alert on 500-rate, not individual events.