ASP.NET MVC WebAPI 404 error

Question

I have an asp.net web forms application running under v4.0 integrated mode.

I tried to add an apicontroller in the App_Code folder.

In the Global.asax, I ad

Answer 1

Ensure the following things

1.) Ensure that your IIS is configured with .NET 4.5 or 4.0 if your web api is 4.5 install 4.5 in IIS

run this command in command prompt with administrator privilege

C:\Windows\Microsoft.NET\Framework\v4.0.30319>aspnet_regiis.exe -i

2.) Change your routing to

RouteTable.Routes.MapHttpRoute(
      name: "DefaultApi",
      routeTemplate: "{controller}/{id}",
      defaults: new { id = System.Web.Http.RouteParameter.Optional }
 );

and make request with Demo/Get (where demo is your controller name)

if the 1,2 are not working try 3

3.) Add following configuration in web.config file