Problem starting the server! (Counter-Strike: Source)

I always go to play on the same server, and recently, at startup, the server began to crash more often with the inscription: Model models/wood_gib01e.mdl not found and models/error.mdl couldnt be loaded. Over time, the problem resolves itself and the server works again, but for some reason the error occurs again, and it is not clear why.
How to solve the problem?