How to fix wii lens reader?

I've not played on the wii for ages. I have recently been playing gamecube and VC games on it. Today, I tried playing on Goldeneye but it said 'Error. Please eject disc and reset the console.' on a black screen. I tried again, but I just got the same message. I tried a different game and that loaded, but crashed after a few seconds. Now I can't play any wii games. Just to clarify, I can still play Gamecube games on it, but not wii. Does anyone have the solution?