I have been trying for hours to get a basic motion study to function properly. I'm beginning to think this problem is a bug. I've compiled a number of videos over the past week, but a certain assembly with a simple gear mate is totally failing on the save function. It calculates fine, and it previews fine, but when I save the avi it freaks out. I tried different codecs to no avail. I've attached a *very watered down version of this assembly for reference. It uses tool box components that were made independent.