HTTP 505 HTTP Version Not Supported

What HTTP 505 HTTP Version Not Supported means

505 HTTP Version Not Supported means the server refuses the HTTP protocol version used in the request. It's rare today, since clients and servers almost always negotiate a compatible version.

Which category is it?

505 is a 5xx code — Server error. 5xx means the server failed to fulfil an apparently valid request. It's the server's responsibility, not the caller's.

Common causes

• A client using an HTTP version the server rejects
• A misconfigured or very old server

How to fix it

• Use a supported HTTP version (1.1 or 2)
• Update the server or its configuration

Other server error (5xx) codes