http://developers.de/blogs/damir_dobric/archive/2010/06/07/wcf-4-0-webhost-failed-to-process-a-request.aspxProblem Description When working with WCF 4.0 hosted in IIS 7.5 you may get following error: WebHost failed to process a request. Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/15510466 Exception: System.ServiceModelenCommunityServer 2008 SP1 (Build: 30619.63)