What is wrong with WCF HTTP Activation?

Could not load type ‘System.ServiceModel.Activation.HttpModule’ from assembly ‘System.ServiceModel, Version 3.0.0.0, Culture=neutral….


This error started occurring all of a sudden. I was using IIS 7 and .net 4.0. The page was working fine and it broke when I checked it next day. What is wrong with my asp.net pages? Well, it’s not problem with asp.net pages or IIS. It looks like a problem when you install WCF HTTP activation module after you install .net 4.0. I installed WCF HTTP activation module to try something else which caused this problem. Take a look at http://msdn.microsoft.com/en-us/library/aa751852.aspx

Fix: Run aspnet_regiis.exe -i –enable on VS 2010 command prompt.