OK... so I must be stupid as everyone else seems to be able to learn Fur Elise 1-2-3, while I struggle with it.
I just started learning the third section where it starts the 8th note repeats of A. In the 2nd measure of this there is a cord that shows c, b, g, e with a flat AND a sharp sign on the b. How is that played???
I pulled out my score, I can understand your confusion, however, if you look closely, you should see (unless my score is incorrect) that the C is sharped, and the B is flatted.
It's difficult to see from the attached picture, but maybe it will help.