Hello, I'm trying to use Reason from Cubase and am having some problems. I can use Reason just fine by itself, but when I try to launch it from Cubase I receive the following error:

"Midi input problem. One or several of the MIDI inputs could not be opened. They might be in use by another application. Open the Preferences dialog and check your MIDI settings".

Then I get the error: "Reason couldn't set up the control surfaces properly. For details, please open the Preferences dialog, go to the Control Surface page and click the red X symbol(s) in the surface list".

When I do this, I get "Reason can't open the MIDI port selected for the control surface. Please make sure that the drivers for the MIDI interface or device are properly installed, and check that no other program uses the MIDI port".

It looks like it is saying the MIDI port is in use (presumably by Cubase), but I don't know how to resolve the problem.

I'm using:

Lexicon Omega audio interface with latest drivers
Cubase SX3
Reason 3.0
Roland XP-10 keyboard

Any help would be greatly appreciated! Thanks!

Caubase will grab the midi inputs of your control surface when you boot it up. If you then load reason in rewire mode, it can't connect to your control surfaces because cubase is connected to them. Try turning off the control surface(s) that you want to use in reason when you boot up cubase. When cubase is fully loaded, turn on your control surfaces, then load reason. Since cubase didn't have a chance to grab the control surfaces they should be available for reason to use. If you want to use the same control surface for both, that could get complicated if possible. (i actually have no idea if it is) If you have a control surface that has a computer control mode (mackie protocol etc) and a midi control mode like the tascam FW-1082, you can control cubase and reason with the same control surface.
hope this helps.

Rewire allows you to send MIDI data between applications. You can tell cubase to route MIDI inputs to Reason devices. Example: All data on MIDI channel 1 to a Subtractor an so on. (I don´t know, HOW to do it in Cubase, but it should be possible).
Shortcoming is, that you cannot use the remote override functions in Reason, because all MIDI via ReWire can only send to a certain device in Reason.