These are the boxes I check; 1) Include body part names in polygon groups 2) Include exact internal names except spaces 3) Include figure names in polygon groups 5) Weld body part seams These I leave unchecked: 4) Include existing groups in polygon groups 6) As Morph Target (no world transformations) I suppose it could be a PC thing, but I've never heard of anyone with a PC having a similar problem. My OBJ's import into Bryce4 and 5 with no problems, I can even export certain parts as OBJ's, or any other format, and reimport them without crashing. I also set my memory allocation for Bryce5 at around 600MB because I do very large scenes.