It appears to me like what you’re having is an issue with SpriteGrabber, not CBEffects, since the error is referring to a line in SpriteGrabber.
So try getting a working SpriteGrabber object and then placing that in the build function (at least I think you’re using that in the build function, since you have the return there).
(as a side note, I’d advise you not to use SpriteGrabber - it appears that it uses the deprecated sprite library and is thus going to be incompatible with Corona soon, as they’re about to remove it)