Getting this error when I try to build the Caliburn.Micro sample project "Caliburn.Micro.HelloScreens" from http://caliburnmicro.codeplex.com

Error: The type 'TDocument' must be a reference type in order to use it as parameter 'T' in the generic type or method 'Caliburn.Micro.Conductor'

TDocument is defined in the the class DocumentWorkspace as

public abstract class DocumentWorkspace<TDocument> : Conductor<TDocument>.Collection.OneActive, IDocumentWorkspace where TDocument : INotifyPropertyChanged, IDeactivate, IHaveDisplayName
{ }

Samples are fixed and compiling again.

Thanks for the quick fix. Can you explain the reson for the error? Jut curious

the class keyword was missing from the abstraction to tell the DocumentWorkspace that the TDocument was a derived object class.

public abstract class DocumentWorkspace<TDocument> : Conductor<TDocument>.Collection.OneActive, IDocumentWorkspace where TDocument : class, INotifyPropertyChanged, IDeactivate, IHaveDisplayName
{ }