Super Smash Bros Brawl disc help?

I finally found my Super Smash Bros Brawl disc afte two years of searching. I plopped it into my Wii and everthing eas working perfectly fine. Right after I chose my character, a message popped up on my screen, saying that the Wii could not read the disc. I cleaned the back of the disc carefully and thoroughly but the same message popped up everytime. I found out that I'm able to go in the Vault, Options menu and the other stuff, but when I'm about to play, the game stops and the message pops up. I've tried everything to get this game working but it just won't play. Is there somethig thatI'm missing? I have no idea what's wrong with the game. Could the problem be the game itself or the Wii? Please help because I really need answers to why this game won't work when it has in the past.