The progress bar of the course overview block in Moodle's current version doesn't read if an activity is hidden or not. This way, if a student don't have access to some activity in the course (something very common) and that activity accounts completion, it's impossible for the student to reach 100%. This is very clear as not a bug, but how it's suppose to work, as the documentation shows:

"The percentage calculation uses the total number of activities with activity completion set, regardless of whether they are hidden or have an access restriction. The only way to make the percentage reflect work assigned to date would be to not set activity completion for activities which are hidden or have an access restriction"

This has been shown very frustrating and problematic for the users of my site.

It would be great to implement a function to the progress bar only calculate in the percentage the activities that are actually available to the student.