How do I fix a “501 not implemented” error?

This usually happens when the URL of a request changes between the request and the Artifactory server. This may be fixed by setting the Artifactory Custom URL Base to the https address of the server (the proxy) or in the case that there is a SSL -> nginx -> Artifactory chain of servers you may need to add/change the following to the header in the middle (nginx) server:

proxy_set_header X-Forwarded-Proto https;

For Apache HTTP: 

RequestHeader set X-Forwarded-Proto “https”

Note: You need mod_header to be enabled