[Same_Thing]

Hey guys I have a problem - when I start l4d2 the passing, he shows an error:
5/ - survivor_bot: UTIL_SetModel: not precached: model/survivors/survivor_teenangst.mdl
I read here somewhere about this problem, when somebody was trying to add l4d characters in l4d2, but the solution was not clear for me. All I know is that it is connected somehow with the plugins) How can I solve this?