I have heard of this particular error occuring once before, but there was no specific resolution in that case. The user managed to fix it, but we were never sure what caused what.
You might try force-recompiling your main VI. You can do this by holding down <Ctrl> and <Shift> and then pressing the Run arrow. Try that, resave, then build the project again. Does it still fail?
You might also try requesting support from ni.com/support to get in contact with an Applications Engineer. It would probably help R&D at NI to have a copy of your application that repeatedly causes this error if it's not classified or anything like that.
Jarrod S.
National Instruments