Hey guys, i made 1 building in gmax and colored it

for i could udnerstand what each thing do what (1 color for walls, 1 for groud, 1 for weapons and more) and saved it as .gmax format and now my RenX can't open it :@ and i tooked almsot 2 hours for made that thing and now RenX dno't let me open it cuz i wanna convert it to .w3d, so any ideas about whats the problem or some1 know a exporter for .w3d for gmax...