HTTP POST Returns Error: 417 “Expectation Failed.”

Question

When I try to POST to a URL it results in the following exception:

The remote server returned an error: (417) Expectation Failed.

Answer 1

If you are using "HttpClient", and you don't want to use global configuration to affect all you program you can use:

 HttpClientHandler httpClientHandler = new HttpClientHandler();
 httpClient.DefaultRequestHeaders.ExpectContinue = false;

I you are using "WebClient" I think you can try to remove this header by calling:

 var client = new WebClient();
 client.Headers.Remove(HttpRequestHeader.Expect);