One thing that is interesting is that X2 is working when X3 isn't. Audio settings are saved separately between X2 and X3 so resetting the X3 settings could fix up your install. Give this a try and let me know if this helps.
1) Make sure SONAR is fully closed and navigate to your appdata folder (paste &appdata% into your file explorer window to get there)
2) Open the Cakewalk folder
3) Open the X3 Folder
4) Locate the file called "AUD" or "AUD.ini"
5) For safe keeping it's best to save this file somewhere. I recommend simply moving the file to the desktop.
6) With the file now moved out of the folder, Make sure your motu is ON and plugged in and relaunch SONAR X3
SONAR will automatically recreate The AUD.ini file with clean settings.