Have you added any new mods/textures/animations/maps into the game?
Also, did you try to change the rendering mode, Direct3D9 instead of OpenGL?
Also check out the (click--->)Big Help Thread (https://feral-heart.com/smf/index.php?topic=10423.msg144821#msg144821), and see if there's something in there that maybe can help.
I'm agreeing with Wolvie here for a second opinion on the matter. I would highly suggest replacing your models folder with the vanilla which indeed can be found in Bawfle's default thread linked below! Which is actually very useful. Good luck! <3