505 HTTP Version Not Supported
The HTTP505 HTTP Version Not Supportedserver error response status code indicates that the HTTP version used in the request is not supported by the server.
It's common to see this error when a request line is improperly formed such asGET /path to resource HTTP/1.1 or with\n terminating the request line instead of\r\n.For example, intermediaries such as load balancers may not handle request lines of a forwarded request as illustrated in the example below.
Status
505 HTTP Version Not SupportedExamples
A 505 due to malformed request-line
In the following example, a client requestsexample.com/dog%20trainers, but due to incorrect load balancer configuration, thepercent encoding in the URL is not handled properly.In this case, the origin server seestrainers instead of the HTTP version, and a505 response is returned instead.A request identifier is contained in the response body for illustration of a way that may help server administrators narrow down the root cause of the problem:
GET /dog trainers HTTP/1.1Host: example.comHTTP/1.1 505 HTTP Version Not SupportedContent-Type: text/html;Content-Length: 123<!doctype html><html lang="en"><head> <title>505 HTTP Version Not Supported</title></head><body> <h1>505 HTTP Version Not Supported</h1> <p>If this problem persists, please <a href="https://example.com/support">contact support</a>.</p> <p>Server logs contain details of this error with request ID: ABC-123.</p></body></html>Specifications
| Specification |
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| HTTP Semantics # status.505 |