That is not very serious, and it is not what I expected from a brand such as Lange.
IF the proto was not working.
I mean that we don't expect Lange to unveil a definitve watch. There may be some aesthetical and mechanical changes on the definitive watch ,and that is, of course, very acceptable, as with time passing, you see that some things are working fine, and others don't.
But a non working proto, while many were dreaming about a real striking watch from Lange, that is not really smart.
IMO.
Best,
Nicolas.