Yesterday we encountered a worrying blocking error when expanding the Application node under a BizTalk Group in the 2006 Administration Console: Failed to create ApplicationNode (Microsoft.BizTalk.SnapIn.Framework) Additional Information: Exception has been thrown by the target of an invocation. (mscorlib) Failed to enable constraints. One or more rows contain values violating non-null , unique or foreign-key constraints. (System.Data) All of the [...]