FIX: When Microsoft Teams FAILS TO PLAY VIDEOS
If you or your Team mates aren't able to play a video in Teams, try troubleshooting with these methods shown in the video tutorial.
Summary of Video:
Check to see if videos will play in the Web browser version of Teams
Upload the video to Microsoft Stream and test the video from there.
If it states that the video stopped working due to a network error, then try plugging into a LAN line or connecting a different wifi network.