Input Error. Lost Controller

Hi.
 
I'm hoping someone can help me.  I use Sonar X3 Studio.  When I launch it it seems to drop the keyboard controller I have connected and this error message comes up:
 
The following audio output devices used by this project are unavailable
You may re assign them to any available device or click OK to accept the default assignment below
Click CANCEL to retain  the original output assignments. These outputs will remain silent until re assigned to an available output
 
Missing Device                                          Available Device
ASIO4ALL v2 HD Audio Output 1           ASIO4ALL  v2 Not Connected 1
 
The only choice the drop down in Available Device gives me is the one in the Missing Device and that is no solution.
What's happening here and how can it be corrected?  My keyboard remain listed in the MIDI devices but it cannot be used.
If this cannot be corrected I can no longer use Sonar.
 
Thanks for any help.  This just started recently.

Hi Zarrg, and thanks for responding.  Yes, this is using the internal PC soundcard via ASIO4All.  When I use my external interface (Pod Studio UX2) and its drivers, this doesn't happen. I don't have a problem working with the interfaces drivers, but what bothers me is this is something that just changed without a warning.  I've been using it this way (soundcard & ASIO) for a year now, since I've been using Sonar and now, out of the blue, this change.  It started last week when I was trying to get my Keystation Mini 32 to work on my PC and a tech from Sweetwater remotely changed the input/output in my Sonar.  But I did do a complete re install of Sonar to get back to the defaults and it's still happening.  When something changes, I don't necessarily have a problem with the changes, but I do like knowing why they happen.
 
John B.