OK. My synth engine communicates fine with my audio interface.  However, no matter what I do it will NOT communicate any MIDI. The little icon beside the synth engine icon is grayed out, and a strike through it.  I KNOW my device is working fine because my PreSonus Studio One 3 works great.  In fact, much better latency, and it also holds the sample rate at 48k instead of switching to 44k. 
Little Help,
KC

Use SO3?

Thanks Dickie, but I don't comprende'.
 

Sorry I don't have the answer for that. But Sonar doesn't control your sample rate. Your previous projects and you control it.
 
BTW he is saying don't use Sonar.

""my PreSonus Studio One 3 works great""
 
SO3=Studio one 3.
 
 

Sonar can mess with MIDI devices. So what is shown in "MIDI" preferences does not correspond to the Windows devices Sonar really listen/send.
* Try to disable all and then enable again.
* If does not work, remove TTSSEQ.INI in the %APPDATA%\Cakewalk\<you sonar version>.
* If still no luck, remove not existing (hidden) MIDI devices in the Windows device manager (there is an option to show disconnected devices).
* If still no luck, remove device in question (in the device manager) and then reinstall it.
 
Well, the advise with SO3 is not bad. Or try Reaper, you can try to open your Sonar projects in it