I have an API methd in .NET MVC which consume a web service from a third party the serviec was working fine two days ago Now when I am calling getresponse it return an exception 400 bad request , THERE IS NO CHANGE IN IMPLEMENTAITON same Api was working two days ago fine , the api provider also said that he has done no change the URL parameters both are same , might be some network issue but why it gives 404 bad request on calling getresponse I did telnet it works fien so what else could be the reason remember I am not checking in browser so no browser based issue I am checking via post man and my method is simple controller method with post verb, no rest based api method like latest 2.0 api rather it is simple controller method.