Could it possibly be a particle issue? Particles are just weird in general, using them in map making can cause problems. I had made a custom texture for a mesh once to use in one of my maps back before the update, and after I added it to the map my particles folder would create duplicates of the particle files after I'd close the window out thus crashing my game each time I'd go back and open it. Maybe there was a certain particle used that is causing these issues and they occur when your camera faces them?
Or it could be that your friend had custom object groups and/or downloaded objects that are no longer compatible with the game due to the update, I've lost objects I can't use anymore because of that so, that could be what's crashing you?
Just thoughts, no real answers.
