More info: I'm trying to combine classes that different students have written into one greenfoot project. Many (not all) of the classes show up with gray lines and indicate that they need to be compiled, but I can't figure out how to make it compile. I am running version 3 without the compile button. If I open and edit classes individually, there are no compiler errors. If I make a minor edit, I can click on compile, but the gray bars don't go away. Help!!