I can't seem to access the Unit 4 lesson documentation. When I click the link, it redirects to the main page. Is that unit still under revision?
Are you talking about the documentation for App Lab? Which link are you clicking?
This URL - https://curriculum.code.org/csp-18/unit4.pdf
It's the "Lessons PDF" link from the Unit 4 curriculum overview page. (https://curriculum.code.org/csp-18/unit4/)
Ah, looks like the PDFs failed to generate when up pushed out the new course. That link should be fixed now. Thanks for the heads up!