For a long time now there has been a crashing issue w/ the raytracer. It turns out there were two seperate causes: - Masking a bumpmapper effect and using reflective or transparent features in the Standard shader would cause secondary rays to access a disposed mask reference during the colorizer pass. - Raytracing a scene and then using the Colormap dialog would cause automatic re-colorizing to occur (to bring the raytraced image up-to-date with the new colormap). Cancelling this render pass would display an "Operation cancelled" dialog and clicking OK would then cause an uncaught exception. Similar badness would happen if you clicked 'Apply' or 'Cancel' in the Colormap dialog and then aborted any raytracing. A fix is available by applying this patch: http://www.daylongraphics.com/products/leveller/download/updates/lev262_486.zip Ray