I'm working on a open source render engine for 3dsmax ( I'm the only developer currently), and I've been struggling with the meshes for weeks, been the most frustrating thing I've ever developed, I did get help the last few days on a 3dsmax dev forum, so now tonight it finally works.
I was able to render out some complex meshes without any issues.
See attached image :)

https://quitter.no/attachment/19052