502 Bad Gateway
A gateway or proxy received an invalid response from the upstream server it forwarded the request to.
5xx · Server error
Typical causes
The application crashed or closed the connection, listens on the wrong port or interface, or is still starting.
On Bex
On Bex, check that the process listens on 0.0.0.0 and the injected PORT and passes its health check. A maintenance-mode custom page that cannot be fetched also produces a 502.
Defined in RFC 9110, §15.6.3