Nil point errors are usually when Carrara encounters what it considers as an "illegal" instance of something - either texture maps or geometry that it doesn't like. Over the years, when I've personally encountered those nasty little things, I'll trouble shoot the scene by importing one object, then closing the scene and reopening. I'll then add another object and repeat the drill until it fails. It's a pain but works 95% of the time. Then when you identify the culprit, you can fire off a bug report indicating that you can repeat it with "object X". That usually gets some attention because it's identified and repeatable. In the mean time, you can continue with your scene avoiding the problem object. Sorry for not replying earlier. I've been just slammed lately and there is no "short" answer to this one. Good luck. Please post back if you find the issue. Mark