If the Default Midi Editor is set to ‘Open List Editor’ or ‘Open In-place Editor’ in Preferences/Editors, clicking on a midi part does not open the correct editor - it always opens the Key editor.
If the default is set to ‘Open Key Editor’, ‘Open Drum Editor’ or ‘Open Score Editor’ it operates as it should.
How come is this now broken??
Simple repro:
Set the Default Midi Editor to ‘Open List Editor’ in Preferences/Editors then double-click on a midi part.
Ruled out corrupt prefs?
Well, I entered ALL prefs in N8.2 by hand (not copied from N7), so I’d like to think that the program is capable of creating and maintaining a fresh prefs file (for a few minutes at least).
I have found that the problem described in the OP relates to the Lower Zone only.
It only occurs if Preferences/Editors - ‘Double-Click opens Editor in Lower Zone’ is selected.
If ‘Double-Click opens Editor in a Window’ is selected the correct editer is used.
So there is an issue with the Lower Zone.