M-Audio Oxygen 49 MIDI controller IS sending data, but Sonar receives nothing. I've checked that MIDI data is being sent from the Oxygen by looking at it in MIDIOX Input Monitor window. I have the latest M-Audio driver installed, I have the Oxygen selected as a MIDI input device and I'm using the MIDI Omni option. What next?
 
Thanks - rev

Have you tried to select M-Audio as explicit input for some MIDI track and start recording the track?
Also with MIDIOX it is possible to "perform filtering and mapping of MIDI data streams", also wrong way...

Is this the first time you've recorded MIDI with this keyboard and/or interface? IOW, was it working before and has now stopped working, or is this a new setup?
 
You might try using a standalone instrument for testing. I'll usually bring up Kontakt or Omnisphere in standalone mode to verify my MIDI connections when nothing seems to be happening. I've got a complicated setup here, so sometimes I forget what's plugged into what. What's your setup? A single MIDI cable into the interface, a separate USB cable, any THRU connections?

Azslow3: Not sure what you meant but note-on and note-off data appears in MIDIOX. That convinces me that the keyboard is sending it. The notes correspond to the keys pressed. Filtering and mapping could not cause that.
 
Bitflipper: I have never, ever in my many years of experience, been able to get MIDI data to trigger a plug in a standalone app like Kontakt. No idea why but when I get a new Kontakt app, I always have to play it inside a Sonar file. In other words, rather than being a quick test, it would be a deeper mystery and more work solving that problem.
 
This should be simple, the keyboard is sending data. I'm 100% satisfied that it is, it can't be sending just to one app, it's either sending or not. The next question is, what setting or config would make the keyboard itself visible in Sonar, but not the data. 

OTOH, if you can solve the mystery as to why you can't play Kontakt standalone, that'll probably also provide the crucial clue you need to resolve your current headache.
 
Bear in mind that SONAR is getting the MIDI data from the driver, and finding out about the driver from Windows. Which is to say, SONAR discovers the MIDI data source the same way Kontakt or any other audio application does. If Windows can't see the driver, neither can SONAR (or Kontakt). 
 
If you click on the Options button in Kontakt, and then the MIDI tab of the Options screen (and click on "Inputs" if necessary), you should see your interface listed there. It should show "Port A" under the Status column.
 
If it doesn't list it at all, then Kontakt can't see or talk to the driver, and doesn't even know it exists. Chances are, Windows doesn't know it's there, either. Go to the Sounds and Audio Devices control panel applet, hardware tab, and make sure your interface is listed there. Also make sure Windows considers it the default device.
 
If it lists it but is showing "Port B", then the driver is incorrectly configured. MIDI-OX would still see it, but SONAR won't.
 
If it lists it and shows "Port A", and the instrument is set for the correct MIDI channel but there is no response when you play the keyboard, then...hmm, I'll have to ponder that one.

revnice1
Azslow3: Not sure what you meant but note-on and note-off data appears in MIDIOX. That convinces me that the keyboard is sending it. The notes correspond to the keys pressed. Filtering and mapping could not cause that.

Yes, that shows keyboard is sending data to the computer and MIDIOX can see the data. But that does not mean MIDIOX is not filtering that data and SONAR is configured correctly to receive what you want.
 
"Computers are good at following instructions, but not at reading your mind" (D. E. Knuth)

revnice1
M-Audio Oxygen 49 MIDI controller IS sending data, but Sonar receives nothing. I've checked that MIDI data is being sent from the Oxygen by looking at it in MIDIOX Input Monitor window. I have the latest M-Audio driver installed, I have the Oxygen selected as a MIDI input device and I'm using the MIDI Omni option. What next?
 
Thanks - rev

You seem to have listed all the correct things to look for in your post. 
 you say " I have the Oxygen selected as a MIDI input device"  
But is that in Sonar? and where? 
Does the little task bar icon light up when you play? 
Are you seeing it in the MIDI track inspectors list of input options for a midi track? 
Under - ( tool bar) Options/ MIDI devices is it showing in the inputs list box and checked?
This is not clear in what you say here.
 
If it is showing, and if it is an input option then it will work.
 
Try this
Insert True Pianos or TTS-1
Test them first using the GUI to see if they are outputting correctly. 
Insert a blank MIDI track, input echo should default to on. 
Set it's input to the Oxygen and omni 
Set it's output to true Pianos or TTS-1. 
 
I know you probably know all this stuff already, but others might read this post who don't, so sorry if I'm talking basic stuff here. If that doesn't work then you have a driver issue. 
I see there are a  lot of choices for drivers on the web site, double check you have the correct one, just to make us happy.   
 
 

Bitflipper and Sock:
 
Thanks to all your combined suggestions, I have that poxy little keyboard working everywhere!
 
In Kontakt Standalone it was set to Off under the MIDI tab. :) In Sonar I just went through the entire checklist and found it working at the end so I'm not sure what it was that fixed it. Input echo does not default to ON for me, maybe it was that simple, I hadn't noticed it wasn't on. 
 
Either way, thanks very much to both of you for taking the time!
 
rev
 

I have just experienced this for the first time my self.  I have been using Pro Audio 9 for midi input and I am trying to transition to Studio 8.5.3.  I use an Ensoniq SQ-1 plus for input.  I have an Audio Kontrol 1 for an interface.  I have the channel I want to input set to Audio Kontrol 1 IN and I can hear the sound assigned to that channel in my monitor.  I click the "R" and it turns red and hit play but the midi data is not recorded.

Dixie:
My best suggestion is use MIDIOX to make sure data is being sent. You can also see what kind of data is being sent. Once you know the right data is being sent, you can concentrate on why it's not being received.
 
Among the things I did:

• In Kontakt, make sure it's set to ON under the MIDI tab
• Remove and install the latest driver
• Remove the driver and see if the Ensoniq is recognized as a generic Windows Device (sometimes a driver isn't necessary).
• Select it as an Input device under MIDI > Devices
• Check that Input echo is ON, for the MIDI track in question
• Set to Omni.