We're having a real difficult time with our users who are taking our course. Essentially, at any point in which they deviate from the linear course, review a previous quiz or video, etc.., when they attempt to move forward, they are hit with a grey screen and the spinning wheel.
As a workaround, we've found that simply republishing the course will fix the issue - but ONLY for that current user's session. After that, another user will experience the same issue. Naturally, it's multiple users, multiple browsers, multiple coutnries, variable course sections. It seems like daily we're getting a new user with the same locked screen at a different part of the course.
We're working through each of the "fixes" from the Adobe forums, but nothing has worked yet.
Again, this is from the user/learner side when they attempt to take the course. And no, we can't remove the backwards movement because it's an educational couse. How can they advance if they can't review what they just learned when they fail a course.