http://developers.de/blogs/damir_dobric/archive/2012/11/26/sharepoint-workflow-trustedsurface.aspxAs I described here Windows Azure Workflow (Workflow Manager) is originally designed to run in the cloud. That means it designed as multitenant application. because of that the Workflow Manager must fulfill several very sensitive security requirementsenCommunityServer 2008 SP1 (Build: 30619.63)