Ensure the trainer is targeting the correct executable ( BlackOpsColdWar.exe ). If you bought the game on Steam but are using a trainer built exclusively for the Battle.net version, it may fail to find the correct memory paths.
High-intensity cheats like "Rapid Fire" combined with "No Reload" can overload the game engine, causing a Fatal Error crash. Try activating only one or two essential cheats at a time. black ops cold war trainer work