There are three primary reasons why lessons may be locked in an HOL Cloud course. See the sections below for help understanding the reasons. These are presented in the order that HOL Cloud "gates" content.
Reason 1: Students have not purchased or activated the course's lab kit.
If the "Enter a Code" and "Purchase Kit" buttons appear on the top right-hand corner of the window, that means the lab kit for the course has either not been purchased or the kit code has not been entered. See our guides here for help ordering or activating lab kits.
Reason 2: Students have not finished previous lessons.
Lessons usually have to be completed in order. If a student hasn't finished all previous lessons a course, they won't be able to move to the next one. Make sure they have completed all the lessons above the lesson they're trying to access.
The lesson in the example below is locked because previous lessons have not been completed, and is ready to unlock as soon as its prerequisites are met.
Reason 3: The instructor has set access dates for the lessons.
Instructors can set lessons to unlock on specific dates. If this is the case, clicking on the lock icon will show a message with the date it will unlock. If a lesson is supposed to unlock on a certain day, students won't be able to access it until that date.
Note: if a lesson is locked but the access date shown has already passed, check the requirements in reasons 1 and 2 yet (purchasing a kit/redeeming a kit code and completing all previous lessons.)