Can't find usb 1 and 2 in the midi devices in Sonar X3 for my MCU pro and extender. Just upgraded to X3 64 bit from Sonar 7 which worked fine.
 
Windows 7 pro
Sonar X3
RME Multiface II

If Sonar can't find a USB device that usually indicates that the driver isn't installed correctly. If you are now running x64 you will need the x64 drivers if there are any.
 
That'd be my starting point even if that involves un-installing and then re-installing the MCU.

The Mackie Control Universal Pro's don't require a specific driver. The are class compliant for both Mac and PC. Suggestions welcome. I need to get up and running again.

You can check with any standalone soft synth either MCU is recognized (so it is SONAR related problem) or not (then it is Windows related problem). In the second case, check the device manager. "Class compliant" is sometimes "plug and pray" like.
 

Doesn't matter whether it's "Class compliant" or doesn't require a specific driver. It still needs to be installed and visible in devices. If it isn't there it won't work.

What's being said  is, you have to check it under midi devices before it will show up under control surfaces.
 

Sonar doesn't normally like to use those sort of drivers. Other software might.  As said, if your new Windows 64 bit OS doesn't have a driver stashed in its bowels then your hooped. I find often older printers and devices that where made for Windows XP will not install drivers automatically, especially with Windows 8.1. As OS systems move on, so must our equipment and you can only hope the company you bought from will supply new drivers. 
Sonar users need to pay attention and only purchase equipment that comes with proper drivers. 
 
I would guess that it might work if you installed the 32 bit version of Sonar, but that sucks, 64 bit matters!