The wii game turned off and it said to check

Try a different outlet to make sure your outlet didn't go bad on you.

Then if you know your on a good working outlet, reseat the power adapter to the WII.

If that doesn't do it then your adapter might be bad so if you can, try another known good working adapter and that should do the trick. If it doesn't then the main board on the Wii is bad and if your Wii is under warranty you'll need to call Nintendo.