I developed a basic wcf service using just a .svc file, and a library If I call the service via debug it shows me a page with some links , between which I find my .svc file : when I click on it I get the following error message :

Name cannot begin with the '%' character, hexadecimal value 0x25. Line 1, position 2.

The .svc file contains the following :

<%@ServiceHost Language="C#"  Debug="true" Service="WcfServiceMessageBasedActivationLibrary1.Service1" %>

where WcfServiceMessageBasedActivationLibrary1.Service1 is the library containing the real implementation.

If I create an application on IIS pointing to the same folders , I get the same error. The error message is nonsense to me, since there is no "name" starting with "%" in any part of the source code. I tried every option that was humanly possible , without any effect. What is the cause of the problem ?