Adding a custom wcf behavior extension causes a ConfigurationErrorsException

Question

I want to add a behavior extension so that my service classes will be instantiated with Ninject. I created a class that inherits from BehaviorExtensionElement and registered it in my App.config. I cannot see anything obvious I'm missing, yet on startup this is thrown:

System.Configuration.ConfigurationErrorsException: An error occurred creating the configuration section handler for system.serviceModel/behaviors: Extension element TestExtension cannot be added to this element. Verify that the extension is registered in the extension collection at system.serviceModel/extensions/behaviorExtensions.
Parameter name: element (...\MyAssembly.dll.config line 42) ---> 
System.ArgumentException: Extension element TestExtension cannot be added to this element. 
Verify that the extension is registered in the extension collection at system.serviceModel/extensions/behaviorExtensions.
Parameter name: element

Here is my App.config:

<system.serviceModel>
<extensions>
  <behaviorExtensions>
    <add name="TestExtension" type="Mynamespace.DependencyInjectionServiceBehavior,MyAssembly,Version=1.0.0.0,Culture=neutral,PublicKeyToken=null" />
  </behaviorExtensions>
</extensions>
<behaviors>
  <serviceBehaviors>
    <behavior name="MyServiceBehavior">
      <TestExtension/>
    </behavior>
  </serviceBehaviors>
</behaviors>

Here is my behaviour class:

public class DependencyInjectionServiceBehavior : BehaviorExtensionElement, IServiceBehavior
{
    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        foreach (ChannelDispatcherBase cdb in serviceHostBase.ChannelDispatchers)
        {
            ChannelDispatcher cd = cdb as ChannelDispatcher;
            if (cd != null)
            {
                foreach (EndpointDispatcher ed in cd.Endpoints)
                {
                    ed.DispatchRuntime.InstanceProvider =
                        new DependencyInjectionInstanceProvider(serviceDescription.ServiceType);
                }
            }
        }
    }

    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
    }

    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase,
        Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
    }

    public override Type BehaviorType
    {
        get { return this.GetType(); }
    }

    protected override object CreateBehavior()
    {
        return new DependencyInjectionServiceBehavior();
    }

}

Answer 1

Turns out the type name needs to be exactly equivalent to typeof(DependencyInjectionServiceBehavior).AssemblyQualifiedName, the same problem which is described here, among many other sites. My earlier understanding was that there wasn't supposed to be any spaces in the fully qualified type name, which turned out to be wrong.