ASP.NET Web Api HttpResponseException 400 (Bad Request) Hijacked by IIS

Question

I\'m writing a Web API service and trying to return a (400) Bad Request if my ModelState is invalid. I do not want a response body to be attached to this. It appears that II

Answer 1

I had a situation where I was calling a WebApi endpoint from another, and having read that HttpClients should be static I made that change. Worked fine for a few dozen messages but then would get intercepted by the self-host instance which would return a 400 Bad Request. There didn't seem to be anything wrong, especially with the initial success, but my original code would add a default header to the client prior to the call. After I made the client static this would have meant that I was adding the header multiple times to the same client. I changed the code to send create and send an HttpRequestMessage instead of letting the client do it, and added the header to the request. Seems to have solved my problem.