ALL VIDEO SHARE

Hello,
I'm having a problem with YouTube videos not displaying on Mozilla Firefox.
Here is an example :
eume.upf.org/resources/speeches/1679-int...022-london-session-6
The video runs on YouTube itself , but in the website with All Video Share it gives an error: "Code 5: The requested content cannot be played in an HTML5 player or another error related to the HTML5 player has occurred."
However, the video runs on the website when using Google Chrome or Microsoft Edge.
The original video is .mp4 format.
Do you have any idea what could be causing this? (I'm not saying it's necessarily a problem with All Video Share.)
Many thanks,
Alan

Kindly look at the attached screenshot  prnt.sc/nAuT19Uy8NlK
It was taken from our Firefox browser.  I confirm the video is playing fine for us here. I doubt you must be using the oldest browser version. Kindly try upgrading to the latest  Firefox browser version.

Hope this solved your issue!

If still the issue remains, kindly let us know the OS and the exact browser on which you check this. So, we can check with the same.

Thanks a lot. I have the latest version of Firefox. However, it since discovered that the same problem occurs if I just embed the video without using All Video Share, so I guess it must be something else with either my website or my browser, but not All Video Share. Sorry to have bothered you.

Then, I doubt a browse add-on or a setting from your browser is causing the issue. Kindly disable your browser add-ons,  restore the browser settings and check again.