WCF, Service attribute value in the ServiceHost directive could not be found

Option One:

This message is often due to an IIS 7 config problem. If you are used to creating a virtual directory pointing to the folder where your service resides, that no longer works. Now, you need to use the "Create Application..." option instead.

Other Options:

• WCF: The type provided as the Service attribute could not be found
• The type , provided as the Service attribute value in the ServiceHost directive could not be found.

This error occurs due to mismatch of Service name in .SVC file. Probably you might have changed the name of the service class that is implementing the interface.The Solution is to open .SVC file and exactly match the Service attribute and CodeBehind Attribute. So your .SVC file should be like

<%@ ServiceHost Language="Language you are using" Debug="bool value to enable debugging" Service="Service class name that is implementing your Service interface" Codebehind="~/Appcode/Class implementing interface.cs"%>. for eg.

<%@ ServiceHost Language="C#" Debug="true" Service="Product.Service" CodeBehind="~/AppCode/Product.Service.cs"%>

This example is for .svc file that is using C# language, with debugging enabled, Service class implementing interface and this class is within app folder with name Service.cs and Product is namespace for Service class.

Also Please make respective change in service config file.

<system.serviceModel>
    <services>
        <service name="Product.Service" behaviorConfiguration="ServiceBehavior">
            <endpoint address="" binding="wsHttpBinding" contract="Product.Iservice">
            </endpoint>
            <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
        </service>
    </services>
    <behaviors>
        <behavior name="ServiceBehavior">
            <serviceMetaData httpGetEnabled="true"/>
            <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
    </behaviors>
</system.serviceModel>

The problem could also be a in a different namespace in svc file as it is in svc.cs file.

In svc file namespace must be in the following format.

Service="Namespace.SvcClassName"

I know this is probably the "obvious" answer, but it tripped me up for a bit. Make sure there's a dll for the project in the bin folder. When the service was published, the guy who published it deleted the dlls because he thought they were in the GAC. The one specifically for the project (QS.DialogManager.Communication.IISHost.RecipientService.dll, in this case) wasn't there.

Same error for a VERY different reason.