Problem advancing the screen...

Have you tried republishing it?

I haven't used captivate projects within an LMS before, so I'm not sure how it works, but I've had a similar problem where an .exe file is playing fine but then it goes completely blank.  Simply republishing it has fixed it every time.

Although, not sure what it means that other users haven't had the same problem.  Are you able to replicate the problem for yourself?

Can't see from the screenshots if the simulation has a Cp playbar on it or not.

If it does, then dragging the little current position pointy thing - I believe that's the technical term   - pauses the simulation.

Could the learner have dragged the postition to say the very beginning of a slide with no objects?

If so, clicking the play button on the playbar should get things back on track.

It's difficult for me to say what's happening without seeing the timeline, but it looks like if the user had pressed something that made the project "Continue" instead of going to next slide and the window faded out.

Is that a possibility?