Validate two UML diagrams and display them in ErrorList window

Question

I want to validate that each UML use case has its associated UML activity diagram (s). Then I want to display them in Error List window. However, debugging the following code, they didn't display any message. How can I display them?

[Export(typeof(System.Action<ValidationContext, object, object>))]
[ValidationMethod(ValidationCategories.Menu)]

#region Consistency Rule 1

public void ConsistencyRule1(ValidationContext context, IUseCase useCases, IActivity AD)
{
 context.LogMessage(string.Format("Use case name: {0} and its associated activity diagram  {1} ", useCases.Name, AD.Name), "101", useCases,AD);
}
#endregion Consistency Rule 1