The class name '?' is not a valid identifier in this lang..

Question

I'm getting this error in VS; The class name '?' is not a valid identifier in this language
What does this mean? There is no line or column where I can find the error and I can't see my design.

I've searched the code for questionmarks (?) but I don't find any.

Also I'm creating a lottery program for an assignment in my C#.NET class.