Simulation videos of "PhET Interactive Simulations (en)" are not playing in my device

This is the information about my system:-

Version: 0.12.1
OS: Linux-4.10.0-30-generic-x86_64-with-Ubuntu-16.04-xenial
Installer: pex
Server: Kolibri internal server
Database: /home/faizan/.kolibri/db.sqlite3
Device name: faizan-sys
Free disk space: 15 GB
Server time: Tue Mar 19 2019 11:02:00 GMT+0530 (IST)
Server timezone: Asia/Kolkata

Hi @faizan591994 can you confirm that it is the videos for PhET that are causing the issue, and not the actual interactive simulations?

Would you be able to post a screenshot of what you are seeing when attempting to view them? Also, if you able to access the developer console in your web browser (pressing F12 in most browsers should show this) any errors (red text) on the console would be helpful for debugging.