3ds Max is not directly backwards compatible unfortunately :(
Depending on the model you could try exporting it as
.3ds / .obj / .fbx from the new version -
then importing it into 2009.
I'd ensure the stacks are completely collapsed, x-forms are all reset and the object is as 'pure' as possible.
Simply opening something made in a newer version ain't going to happen.
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David Chappell
Freelance Motion Graphics / 3D
http://www.IncidentalTrees.co.uk
