Xtremes Crop/Clip tool doesn't function when there have been filter/effects applied to it. This I think is by design due to the non-destructive nature of Xtremes cropping/clipping, as the effect/s would need to be re applied and the outcome would look slightly different for the resized image. Therefore a bitmap copy is usually required before cropping can take place.

Having said that, you could always use 'Clipview' instead?