check instructions vs validator
I have run into numerous issues validating, where the name of the object or the requested exercise conflicts with the validator. eg. Collections 4.1 asks for a dictionary to be created, but when you validate a new dictionary, the error says we need to create a list. It might be good to go through exercises and make sure the instructions match the validator.
Jeremy Kincaid commented
Also on Visibility and Accessibility Modifiers 4.1 it asks you to make a protected property called "GraduationYear" yet when I go to verify it says I need a property named "Order".