I've found out that I have
exactly the same problem with AI mesh that was accidentaly demonstrated in Hiner's tutorial (
http://www.youtube.com/watch?feature=player_embedded&v=bnipiwUW7rk#t=2660 - right timing in the vid, or 44:20).
The problem is, when I hit the "Create AI mesh", the game crashes. Unlike Hiner, I didn't cancel it so we've got an error message to ponder on which says: "Too many verticles(67736) for one mesh, split the mesh "AI_vertex_mesh" (material: "vertex_color_blend_mat)".
Hiner solved this by doing the meshing manually, which is definitely not the case for me - I've got a scene of the biggest size available and manually meshing it will take, what, a month?
The weird thing is that the button worked fine for me in somewhat 1.153 or close, back then when I was scenning a year or two ago. And since Hinter didn't have giant scene size or many props in it, this should not be the cause for me as I first suspected.
Any ideas how to fix that?