I'm having a problem saving hierarchy layouts. I have a MSTS model that requires the 3DC hierarchy to be in a certain order before export else the model will crash MSTS. Trouble is that 3DC refuses to save the hierarchy that works for MSTS and changes it upon saving to a hierarchy that doesn,t work. Every time I wish to export this model to MSTS I have to modify the hierarchy to the version that works, then export. If I save this heirach, next time I open this model in 3DC the hierarchy has returned to its pre-modified version.

Is 3DC actually re-writing my hierarchy for some reason?

Mike.

I'm sorry, but 3D Canvas doesn't preserve hierarchy order in any way. It doesn't deliberately change it (unless you use the Train Simulator Wizard), but doesn't make any attempt to preserve order either.