'Error opening midi in device' Popup

What does this mean? Won’t let me record

I’ve been recording tracks with no problems today. All of a sudden when I hit ‘record’ I get a popup saying ‘Error opening midi in device’. I didn’t change a thing, and am simply recording acoustic guitar through a mic. What do I do to get rid of that popup so I can record again? Thanks.

Edited to add–I just figured it out! Sorry you had to read this!

Same thing is happening to me. Also, when I select File>Close the program shuts down.

Edited to add--I just figured it out! Sorry you had to read this!
What was it? Others might benefit if they have the same problem.
Quote (DC3443 @ April 23 2005,18:27)
I've been recording tracks with no problems today. All of a sudden when I hit 'record' I get a popup saying 'Error opening midi in device'. I didn't change a thing, and am simply recording acoustic guitar through a mic. What do I do to get rid of that popup so I can record again? Thanks.

Edited to add--I just figured it out! Sorry you had to read this!

Same thing happening here, all settings triple checked.
I'm using the MS synth. The Midi file plays fine in Media Player.
Installed the beta .Net build just before it started. Uninstalling the beta and re-installing build 1811 was no help.

Any ideas?

Jeff