[iis] Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

Ok, finally got it.

Change this line in %windir%\System32\inetsrv\Config\ApplicationHost.config

<add name="ServiceModel" type="System.ServiceModel.Activation.HttpModule, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler" />

To

<add name="ServiceModel" type="System.ServiceModel.Activation.HttpModule, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler,runtimeVersionv2.0" />

If this is not enough

Add this following line to the Web.config

<system.webServer>
  <modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>