If you see this error when you are hosting in IIS then most probably you have multiple IIS bindings per scheme in your web site. WCF in .Net Framework 3.0 ,out of the box, does not support multiple binding per site, but this can enabled by extending the System.ServiceModel.Activation.ServiceHostFactory, and providing a CustomServiceHostFactory. CustomServiceHostFactory picks the appropriate base address for the application. The Factory attribute in the ServiceHost directive is set to the CustomSerivceHostFactory.
The only drawback is every developer hosting their application will need to change the svc file to provide the CustomServiceHostFactory, which picks the appropriate base address.
public class MultipleIISBindingSupportServiceHostFactory : ServiceHostFactory
{
retAddress.Add(address);
}
<%@ServiceHost Factory="NS.MultipleIISBindingSupportServiceHostFactory" Service="CalculatorService" %>