Hello,
after upgrading to Cubase 8.5 I can’t really record MIDI with a MIDI Keyboard. When I press pitches above middle C on my keyboard random windows will pop up and/or Cubase will start executing commands.
For example, pressing a middle C on my midi keyboard will bring up the “save as dialog.” Pressing Bb will show me the history menu. Some other midi notes will undo and remove midi clips… 
working for 5min with MIDI I some how ended up having 74 versions of my project!!!
That’s not funny, please fix ASAP!!!
I am working with a MacBookProo 2011 model under OS 10.9.5
Iannis