System.Net.WebException: The remote server returned an error: (411) Length Required.

This is a pretty common issue that comes up when trying to make call a REST based API method through POST. Luckily, there is a simple fix for this one.

This is the code I was using to call the Windows Azure Management API. This particular API call requires the request method to be set as POST, however there is no information that needs to be sent to the server.

var request = (HttpWebRequest) HttpWebRequest.Create(requestUri);
request.Headers.Add("x-ms-version", "2012-08-01");
request.Method = "POST";
request.ContentType = "application/xml";

To fix this error, add an explicit content length to your request before making the API call.

request.ContentLength = 0;