Why do I get the error message "Unsupported Media Type" ?

When sending a message to Tradeplace, you are getting an error message that states "unsupported media type". Here is how to correct this

There are few HTTP header parameters to provide in your request. Content-Type is one of them. It is quite common that by default this value is set to : text/plain.

Using this value will fail and gice you this error. Make sure you add this parameter in your HTTP request header : Content-Type: text/xml

Then you can resend your request, it will go through.