101101 Switching Protocols
The server is switching protocols as requested by the client via an Upgrade header.
508The server detected an infinite loop while processing the request (WebDAV).
A WebDAV operation encountered a circular reference. For example, a PROPFIND with infinite depth on a resource that references itself, or a COPY/MOVE that would create a recursive structure.
Check your resource structure for circular references. Use Depth: 0 or Depth: 1 instead of Depth: infinity. Remove any symbolic links or bindings that create loops.
101The server is switching protocols as requested by the client via an Upgrade header.
425The server is unwilling to process a request that might be replayed, to avoid potential replay attacks.
451The resource is unavailable due to legal demands, such as censorship or court orders.
413The request body exceeds the size limit configured on the server.
504A gateway or proxy server did not receive a timely response from the upstream server.
421The request was directed at a server that is not able to produce a response for the combination of scheme and authority in the request URI.