I unpacked the gamedata folder and the game crashes

before the crash, the game copies the error log to the clipboard - open any text editor and paste the log there. If you did not touch the archive itself, delete the gamedata folder, everything will be as it was.

the gamedata folder is broken, to be more precise, it is "unfinished", the game also crashes due to the merging of mods or the engine simply does not stand up. Also, look at what version the mod was made for.

perhaps the program is somehow broken, or you already had a game data in the folder with the game and the original one was mixed with the modified one.