i also have the same problem with the compiler warning when i use the line of code to get a list of class objects and i can't wait for a the post that identifies the problem and a solution. It's quite a nail biter knowing that I'm getting a warning and hope nothing breaks
The warning is really nothing to worry about. The next version of Greenfoot will suppress it.
But when I want to export a game with this compiler warning, I can't open the game in the exported mode...
Because of that I went back to version 2.0.1 ;)
I think I know what you mean; however the problem isn't because of the warning. It's a separate problem that will also be fixed with the next Greenfoot version. It's fine to use 2.0.1 for now if that works for you of course.