Category "nsopenpanel"

NSOpenPanel, NSSavePanel runModal dismisses immediately with cancel, but only on M1 running 11.4

I have one user who reports that the Open and Save panels have been "auto dismissing". ie the Open Panel dialog appears then immediately dismisses itself, takin

NSDocumentController.openDocument not allowing selection of custom file type

I suspect this is a finicky configuration issue that I'm getting wrong with Document Type / UTI declarations in my Info.plist, but have tried several things and