There's nothing about that VI I can imagine causing an error on build. You might try doing a force compile of your app to track it down. Try opening up your top level VI, hold CTRL+Shift and hit the run arrow at the same time. If it gives you a broken arrow, you can bring up the error list to try to find it. Maybe this will help locate the problem. If you haven't already, might not hurt to do a mass compile of the SPC VI's also.