There are many reasons for that, but at first check if...
1. Cheat is for that game and this particular game version, thus be sure to use CS2 cheat for CS2 game
2. Cheat file might be just outdated, due to game update
3. If this is .DLL file, there might be a need to inject it by using special method e.g. manual map or standard injection
4. If there is error, probably this is lack of
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