WCF Service Returning "Method Not Allowed"

If you are using the [WebInvoke(Method="GET")] attribute on the service method, make sure that you spell the method name as "GET" and not "Get" or "get" since it is case sensitive! I had the same error and it took me an hour to figure that one out.

Your browser is sending an HTTP GET request: Make sure you have the WebGet attribute on the operation in the contract:

[ServiceContract]
public interface IUploadService
{
    [WebGet()]
    [OperationContract]
    string TestGetMethod(); // This method takes no arguments, returns a string. Perfect for testing quickly with a browser.

    [OperationContract]
    void UploadFile(UploadedFile file); // This probably involves an HTTP POST request. Not so easy for a quick browser test.
 }

The basic intrinsic types (e.g. byte, int, string, and arrays) will be serialized automatically by WCF. Custom classes, like your UploadedFile, won't be.

So, a silly question (but I have to ask it...): is UploadedFile marked as a [DataContract]? If not, you'll need to make sure that it is, and that each of the members in the class that you want to send are marked with [DataMember].

Unlike remoting, where marking a class with [XmlSerializable] allowed you to serialize the whole class without bothering to mark the members that you wanted serialized, WCF needs you to mark up each member. (I believe this is changing in .NET 3.5 SP1...)

A tremendous resource for WCF development is what we know in our shop as "the fish book": Programming WCF Services by Juval Lowy. Unlike some of the other WCF books around, which are a bit dry and academic, this one takes a practical approach to building WCF services and is actually useful. Thoroughly recommended.

I ran into this exact same issue today. I had installed IIS, but did not have the activate WCF Services Enabled under .net framework 4.6.

It sounds like you're using an incorrect address:

To access the Service I enter http://localhost/project/myService.svc/FileUpload

Assuming you mean this is the address you give your client code then I suspect it should actually be:

http://localhost/project/myService.svc