找不到配置绑定扩展名'system.serviceModel / bindings / pollingDuplexHttpBinding'

Question

Problem

I'm getting the following error whenever I try to load out .svc url (Local)

Configuration binding extension 'system.serviceModel/bindings/pollingDuplexHttpBinding' could not be found. Verify that this binding extension is properly registered in system.serviceModel/extensions/bindingExtensions and that it is spelled correctly.

Enviroment

The project was build by a ex colleague of mine, who I can't reach. It's a webservice build in .Net Framework 4

I get this error when I attempt to gain access to our .svc file

In the web.config I have this setting:

<system.serviceModel>
  <extensions>
    <bindingExtensions>
      <add name="pollingDuplexHttpBinding" type="System.ServiceModel.Configuration.PollingDuplexHttpBindingCollectionElement, System.ServiceModel.PollingDuplex, version=3.0.0.0, Culture=neutral" />
    </bindingExtensions>
  </extensions>

which is later used as <endpoint address="" binding="pollingDuplexHttpBinding" contract="<ourcompany>.DataService.IMessageService"/>

Attempts

In regards to other posts about this error I have already tried:

Installing Dot net 3.5 SP1

Removing the line from web.config

Reinstalled IIS

I have no idea what to do, or how to fix this.

The strange part is that it does work on our live server, but not on my own computer for testing purposes!

Answer 1

Refer - Unrecognized element 'pollingDuplexHttpBinding' in service reference configuration

<!-- Register the binding extension from the SDK. -->
<extensions>
  <bindingExtensions>
    <add name=
        "pollingDuplexHttpBinding"
        type="System.ServiceModel.Configuration.PollingDuplexHttpBindingCollectionElement,System.ServiceModel.PollingDuplex, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
  </bindingExtensions>

The difference here is, Version=4.0.0.0 and PublicKeyToken=31bf3856ad364e35 .

You can get more information on the Section "To use PollingDuplexHttpBinding" section of - How to: Build a Duplex Service for a Silverlight Client .

Good luck. :)