Why does the discussion board state it is closed for comments?

You can view the discussion board questions ahead of time by clicking on the Discussions tab in the left navigation bar. If you have not completed all items in the Unit previous to that discussion board, it will be closed for comments. You need to complete all items in a Unit before you are allowed to move on otherwise content will be closed.

For example, let's say you have only completed Unit 1 and you click on the Discussions tab to read a the discussion board question for Unit 3.3. The Unit 3.3 discussion board will be closed for comments until you complete Unit 2.