Cutout is part of Illnab's plugin pack (illnabPlugins.dll).
Unfortunately - if you remove the dll then the other effects ( Alpha Mask, Cutout Effect, Advanced Greyscale, Point Warp, Polar to Rect) won't work either. It's all-or-nothing I'm afraid
If you're not using the other effects, then simply remove the dll mentioned.
I'm not sure if reinstalling the stand-alone cutout effect (from the dll link in the first post of this thread) will reproduce the error or not.