I crash evreytime I go into third person or when I see other players and a error apears saying im missing a sertant model when im not.......

Have you tried completely reinstalling svencoop?

Actually im getting tired of sven(Crashing) so im downloading it right now, hopefully that will work

And it's not a good idea to replace your models if you don't know what you are doing, replacing models can be a dangerous thing to do, the only reason why you should be getting model missing errors.

i hate that error
i tried the model replacement through the entity and i got that error

Actually Ive been replacing model alot and ium to teh point where i know what to do the only models i replace are the weapon and npcs,etc I really dont replace serius stuff

Well it looks like reinstalling sven worked, also I think it helped with some of the crashing problems to