Did you download hacks for it and are they already in the folder? If they are,
1) Take the hacks out and play legit because you're computer will never allow hacks and you will always have this problem if you try to hack.
2) If it still dosn't work, reinstal
3) If it STILL dosn't work, check the requirements.
4) If it STILL dosn't work, don't bother tryin agian.
Note: The server may have just been down so try agian now.