Strange message

I have seen this strange message come up in Cubase 5.0 about something being closed because of too many inputs. I don’t recall the exact wording (it was a few hours ago when I was working on the DAW), but I haven’t seen this before. I had opened an old project I’d created in Cubase SX, and this message appeared, as well as the usual “unmapped inputs” box. I now know how to fix the “unmapped inputs”, but this new one is worrisome.

Secondly, I’m having trouble making some of my VSTIs to work. When I bring up Kontakt and create a track for it (Cubase offers to do this, so I accept), Kontakt shows up and I select the instrument I want to use. Generally, since I am a longtime Hammond player, this will be “Vintage Organs”. However, I don’t get any sounds out of it. When I play the keyboard, I can see meters jumping in the mixer, and also on the Kontakt screen, but only the red (right-hand side) MIDI bar flashes up and down, not the green one beside it (as they both do in any other MIDI channel). There is no sound. I have tried switching MIDI channel numbers in the Inspector and on the Kontakt screen to the MIDI channel I think I’m using, but to no avail. I will post my solution if I figure it out on my own, but if anybody does know how to fix this, I’m listening. Thanks.