Hi,
I am looking into this further because I foresee a fair amount of step files in my future. I'm working with seven step files that make up a machine. When I import one file with default settings, except for I turn off UVs, Normals and layers. and it imports in 22 minutes. When I use best practices with Normals and Uvs and Combine set to topology, scale based tessellation, it crashes C4D after 55 minutes while processes UVs. That's why I tried it with UVs off. When it crashes the Status bar says it's 93% thru processing UVs, and it's happened several times at that point.
Any thoughts would be helpful,
Tom

Could you give me settings that would normally open a complex step file?
Thanks

I've received several Step files from the same source where some open just fine and others don't. Size seems to be the issue. The larger one I've let alone to open for several hours with no luck. Is there a size limit C4D has for Step files? The ones above 250mgs seem to be an issue. I've downloaded a trial of rhino and got them to open there but what to do then is the issue. If I resave as Step they still won't open in C4D. If I make FBXs they become ridiculously heavy.

Any thoughts?