You are missing a (custom) checked exception. Don't forget that with Exception you can catch runtime exceptions as well. That's why the code compiles. But that's not what the study guide provides as an example. It uses a checked NoMoreCarrotsException and that's the difference with your code. So if you are too lazy to create a custom checked exception (like NoMoreCarrotsException) try changing all Exception occurences in your code with IOException and see what happens.
Hope it helps!
PS. In Java we don't use underscores in package and class names.