405 method not allowed Web API

Question

This error is very common, and I tried all of the solutions and non of them worked. I have disabled WebDAV publishing in control panel and added this to my web config file:<

Answer 1

I had the same exception. My problem was that I had used:

using System.Web.Mvc; // Wrong namespace for HttpGet attribute !!!!!!!!!
[HttpGet]
public string Blah()
{
    return "blah";
}

SHOULD BE

using System.Web.Http; // Correct namespace for HttpGet attribute !!!!!!!!!
[HttpGet]
public string Blah()
{
    return "blah";
}