I do.
Go to control surfaces. Either in Preferences in the case of X1-New Sonar or Options-Controllers/Surfaces in 8.5 and earlier.
Remove all control surfaces you see in there. now restart Sonar. the error will / should be gone.
Now, if a control surface is in there that you have hooked up and expect to be using now, then what
has happened is the control surface dll is not registered with windows. A process that usually happens when the control surface is initially installed so reinstalling it should get the surface going again after reinstating it in Sonar. There is a way to hand register the dll but you need to know it's file name and it's location. But there is a condition where everything is otherwise ok, but the control surface dll is a 32 bit one in 64 bit sonar or visa versa - This is a no-no with no work around as will also produce this error.
To register a dll with windows you do it like-a so:
If on XP, open a command prompt by going, WIN+R and typing CMD and press enter.
If on Win Vista or later you must open the command prompt as administrator.
Then:
regsvr32 <path to the control surface dll> /u
regsvr32 <path to the control surface dll>
Example: regsvr32 c:\mycoolsurface\mycoolsurface.dll
The /u command un-registers what may be there. I do that for good measure whenever re-registering.
:Ron