Oh no! It's possible the Community Lookup Key you were given is for an expired community. No worries though! Shoot us an email at firstname.lastname@example.org with the name of your professor and the class you are looking to join and we will send over the correct Community Lookup Key.
Please note: The community lookup key will have the following format: XXXXXXXX-XXXX-XXXXXXXX-XXXXXXXXXXXX. It can only be used to find your community. The lookup key is not an access code or a coupon so it cannot be applied in the coupon field at checkout.