Why is my animated with Mecanim character (enemy) not visible in game (play) mode?

Hi! I’m an experienced game developer and all problems I can solve, but I can’t understand why my animated (with Mecanim) characters (enemies) sometimes aren’t visible in game(play) mode. I can do nothing to fix that. When I restart Unity 4.2, they are visible again. It’s the only way I know to solve this irritating problem. Everything is OK in Scene (Edition) mode, but when I hit “Play” they simply disappear. Not always, but often. They exist in the Hierarchy and in the Scene. There’s voice, even Halo I added; they even can be shot down (I see the red cross-hair and the Halo); there’s all but not visible mesh. There aren’t such problems with other game objects. Is it a bug in Unity? Please tell me if you have the same problems. Or maybe somebody from the Unity team explain me this strange behavior.

Might it be that you have some custom shader going on or custom mesh generation? Unity culls objects early depending on their bounds. That means that if some object’s bounds are wrong (e.g. they aren’t “bounding” the visual representation of the object), objects might get culled although they should be visible.