Bug(?) Blank Version Warning

opening a quite complex Rh6 file, saved small on the Windows side,
opening on Mac - the Version Warning Dialog stays white / blank.
AutoSave Disabled
Your file xxx.3dm is a Rhino V6 file.
not showing
maybe calculating the meshes somehow interferes with the dialog.

workaround is quite simple:
just press enter while Rhino has focus.

Version 7 (7.11.21264.11002, 2021-09-21)
mac os x 10.15.7

@JohnM - is this similar to when we had Rhino hanging on some files where a dialog was not drawing or not in front, something like that?