Revit was unable to identify any spaces. If you are sure that spaces have been created in the project, please check the Project Phase setting to verify that the Project Phase matches the phase in which spaces have been defined in your project.

public static FailureDefinitionId NoSpaces { get; }

Public Shared ReadOnly Property NoSpaces As FailureDefinitionId
	Get

public:
static property FailureDefinitionId^ NoSpaces {
	FailureDefinitionId^ get ();
}