After my IIS server got some updates, it looked like I started getting the “Could not load type “System.ServiceModel.Activation.HttpModule” from assembly “System.ServiceModel, Version=220.127.116.11, Culture=neutral,PublickKeyToken=b77a5c561934e089”
It looked to me as though I needed to reregister Asp.Net 4.0 dlls. And AspNet_RegIIs is the answer.
Run : aspnet_regiis –iru
Aspnet_Regiis can be found in one of the following locations (based on your OS type)
%windir%\Microsoft.NET\Framework64\v4.0.30319 (64-bit machine)