blender crash in game mode when replacing obj.

as the title say every time i replace an object with another one it crash in game mode. anyone with the same problem?
also sometimes i get error messages while importing objects, I read that its a bug of the latest version, then i installed a previous one but still the bug. any sugg.?

what do you mean by " replace an object with another one"?
Using the “replace mesh” Actuator?! It works well for me!