Thanks! I will check it out!

Sorry for the delay. So, your last comment prompted me to explore further. The crash is not actually in pushViewController, but in the init of a subview of a subview in the new VC. These subviews are all programmatically defined and so have no outlets to connect to IB. Oddly, the crash occurs between the viewWillAppear() of the sub-subView and its viewDidAppear()! At end of viewWillAppear, the subview (a collectionView) is entirely populated. No viewIsAppearing is available.

Your comment about the system initially stuffing [NSNull] as arguments got me exploring further. The crash is actually not in the PushVC, but rather in the units of one of programmatically defined (not IB) subviews in the new GlyphSelectViewController. I’ve been driving for the past two hr, and just got back to my laptop. Hopefully I can sort this out. It’s in a subview of a sub view…..