DependencyProperty could not be registered

System.InvalidOperationException: DependencyProperty 'logon' could not be registered. A property with the same name already exists for type

If you ever get this error, and all the usual tricks don't seem to work, try building the project on the commandline.

Error 1 Could not create activity of type 'Coder1.Statemachine.SubWorkflow.AssignCaseToAdvisor'. System.InvalidOperationException: DependencyProperty 'logon' could not be registered. A property with the same name already exists for type 'Coder1.Statemachine.SubWorkflow.AssignCaseToAdvisor'. at System.Workflow.ComponentModel.DependencyProperty.ValidateAndRegister(String name, Type propertyType, Type ownerType, PropertyMetadata defaultMetadata, Type validatorType, Boolean isRegistered) at System.Workflow.ComponentModel.DependencyProperty.Register(String name, Type propertyType, Type ownerType) at Coder1.Statemachine.SubWorkflow.AssignCaseToAdvisor..cctor()

To build the project on the commandline write:

C:\projectfolder>devenv Projectname.sln /BUILD Debug

denev apparently clean some folders, more efficiently than a solution level "clean all" in Visual Studio