During reading and posting in this recent thread;
http://forum.cakewalk.com/Control-Surfaces-for-Sonar-m2907921.aspx
I found out that the Sonar X-series doesn't play nice with the Mackie Control protocol. It seems to work in some cases, but in many cases after setting up the Mackie Control-enabled controller, Sonar displays "connecting" and simply never does connect. This goes for NI Maschine, the Behringer X32, the Yamaha Motif XF series and possibly/probably others.
 
I have personally verified that Maschine works fine at least in Ableton 9 via Mackie Control Protocol on the same system, and yesterday I was controlling Logic 9 via an X32 on a different system. I've only found the Motif reference here on the forum somewhere, no personal experience. There were actually quite a few remarks on the Mackie Protocol failing on many different systems/installations. While it is of course entirely possible that there is some flaw with these devices, or user error, it seems at least Sonar is a common denominator.
 
In all fairness, I use Neyrinck's V-Control Pro from my iPad with Sonar, and whether I set it specifically to Sonar or Mackie Control does not make a difference.
 
Can any of the bakers comment if this is a known bug or limitation?

Oh no! My old Radikal SAC-2.2 controller may not work then. I was hoping to try the Mackie Emulation with my new DAW because the Radikal's USB interface isn't an option under Windows 7; it's a legacy product that will never get new drivers. I will be following this thread. 
 

Can we get some kind of feedback from Cakewalk on these issues?  I've also posted in another thread about the Mackie control (and more specifically to my case, the Behringer BCF2000 using the Mackie protocol).  Everything worked great in 8.5, some things were broken in X1 (and apparently not only not fixed, but not addressed) in X2 or now X3.  Meanwhile, the Mackie Control dll file hasn't been updated in many years.
 
Again...it's broken and it didn't used to be.  Please fix this - or at least let's get some sort of official commentary about whether you are intending to at some point.  This isn't a "it doesn't work the way I want it to" issue.  It's a "doesn't work like it's supposed to and the way it used to" problem.
 
If you check out my video on my site about how to use the BCF2000 in Sonar (http://blades85.com/music/sonar/88-specific-topics/82-behringer-bcf2000-part-2-use-in-sonar) and see the part about the EQ, that's one of the parts that no longer functions.
 
Feedback would be appreciated.
 

I don't believe this to be true. I think if the OP is using a USB connection for his MCU then I would look at the port being used. From what I understand there are two drivers associated with the MCU. One needs to be sure one is using the right one. 
 
Because I use a USB MIDI port to hook up my MC I don't worry about that.  

John - regardless of the method the OP was using to connect the device and the error received, there are unquestionably issues with the way the MCU driver is used in X(whatever).  There are several threads running right now about the issues and the lack of updates to fix them.

I have 4 bcf2000s running under mackie emu in all sonars up to x3 with no issues whatsoever.
That said:
 
Mine are hooked up using standard old midi cables into a midisport 8 x 8 so they stay where they should be day after day.

Blades
John - regardless of the method the OP was using to connect the device and the error received, there are unquestionably issues with the way the MCU driver is used in X(whatever).  There are several threads running right now about the issues and the lack of updates to fix them.

What I am saying that the driver is not always at fault but user error and the error is selecting the wrong one. This means that it provides 2 ins and two outs. Selecting the wrong one will give that message.  I don't have the MCU thus no USB out or in, just MIDI. I never had any issue with any DAW finding and using my MC. In this I am like Bitman. 
 
 

Like I said, using the exact same settings on other DAWs on the same system works fine. It's also not "completely broken", my V-Control Pro works perfectly. But something is up, and it would be good if someone from Cake could comment.

John - and what I'm saying is that IN MY CASE and many of the others in other threads, it's not a simple matter of user error.  This is a while section of the device that no longer does what it used to do.  The EQ section does not work right.  The Prochannel EQ is not controllable the way that the per channel EQ was before.
 
Bitman - can you verify the EQ part?  If you check out the video link I referenced (http://blades85.com/music/sonar/88-specific-topics/82-behringer-bcf2000-part-2-use-in-sonar) and go to the part that's about 2/3 the way through, I go over the "track EQ" settings.  This has not worked for me under X1 because the track EQ is now part of the Prochannel and behaves differently than it did under 8.5 etc.  Does this control mode somehow work for you?
 
There are other parts that are off as well, but this is the one that is the most obvious to me.  I'd like it to work the way it used to.  I'm guessing that the way that the PC EQ is exposed to the Mackie dll is the issue here and also assuming that the new EQ is the same in that regard as the one in X1.
 
Looking forward to your thoughts.

Neither the track EQ or Compressors (on the DYN button) work as they used to in 8.5 an earlier. It is my pet (only?) peeve with the X series and one I'm hoping gets addressed at some point. I currently use the MIDI section of my ZED-R16 with ACT for PC control but it would be much better if I could get at it from the MCU.
 
IIRC in early X1 versions the EQ worked okay, I think it changed at X1b or c. Or perhaps even X2 I can't remember TBH. I posted a thread on all the other MCU niggles some of which have never worked and some that changed with the introduction of X1. That thread with list is HERE - might be incomplete now but it was current for me then.