http://developers.de/blogs/damir_dobric/archive/2009/04/10/declarative-workflow-services-4-0-error-instancekeynotfoundexception.aspxProblem Description When working with declarative workflow services, you may get following error: System.ServiceModel.Core: Throwing exception: System.ServiceModel.Persistence.InstanceKeyNotFoundException: The requested operation could not complete becauseenCommunityServer 2008 SP1 (Build: 30619.63)