Help: Network error of Academy courses

During the courses the video is not working.Here reported as:hlsis-lite Network Error.
But the other applications are just fine.
Have you ever met this?Is there any solution?
Thank you very much for your attention!

Just refresh. Sometimes network errors happens because of slow connections or server response timeout.

Regards,
Karthik Byggari

Yes that happens.Thank you Karthik!