I've been trying to scale yav2_bldg_arena_striaght_2 to 1.8 scale in XSI. When I scale it in XSI everything scales noramally, however in ZE I can see that the lowrez model isn't scaled, and when I try to run in game is crashed on load. The debugger can run the map fine, however I notice that while most of the model is scaled, the collision and lowrez are not scaled.

Have you selected the model, the lowrez, shadow, or the dummy null?
You should select the model, scale it to 1,8 and then press "Freeze M". Continue with every other msh, too. You need to scale the shadow volume,... too.

hmm, I selected everything and the result in XSI was that collision and lowrez where scaled 1.8^2 times, however in game it came out fine.