Yupp I did. I'm with you so far and I have followed the tutorial many times. I've managed to create several tools that work. For some reason I can't figure out why this one doesn't. The references are there for my solution but this class wont add up.
It is some part of the initial sequence that generates an error. It's either row 6 or 12 in the partial below...
namespace TestDuplicateSheet
{
[Transaction(TransactionMode.Manual)]
public partial class ThisApplication : IExternalCommand
{
public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements);
public void DuplicateSheet()
{
UIDocument uidoc = commandData.Application.ActiveUIDocument;
Document doc = uidoc.Document;
ViewSheet vs = doc.ActiveView as ViewSheet;