I got this nasty 401 unauthorized error from my code all of sudden, I don’t really know why and what’s causing it. I used Fiddler as a proxy to see the request header and all of sudden it works but then removing the proxy again brings back the 401!!!

So after googling for a while i found something interesting about browser was requesting for authentication level etc therefore even if you pass the basic security header then it will just simply ignore it. So I played around with the code below and it fixes my issue

WebRequest request = WebRequest.Create(source);
request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;