Code-pre-gfx-mp.ff Download Modern Warfare 2 ((link)) Here

The .ff extension stands for "Fast File." These are compressed archive files used by the IW Engine (the game engine used by Infinity Ward). The code_pre_gfx_mp.ff file specifically holds textures, models, and scripts that need to be loaded into memory before the main multiplayer map starts. Without this file, the game will likely crash on startup or fail to load multiplayer matches.

or a when launching multiplayer.