[DarkSkull]

Just copy pasting all the things correctly should work. Make sure you have all the includes that it mentioned on top of the filterscript and also like enzulikeS said, the only difference is put OnFilterScriptInit() to OnGameModeInit() and OnFilterScriptExit() to OnGameModeExit(). Also, Make sure You DO NOT have the line #define FILTERSCRIPT or copy that from the script.

If you are using givemoneyex, You have to integrate that into the fishing script. Changing all the GivePlayerMoney to GiveMoneyEx should fix that. You should do this for all the diff anitcheats you have on you GM that might interfere with the filterscript.