What other site? Steps to replicate? What security software besides MS Defender are you running? Did you try with Firefox in Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#search

Hi Gene, can you describe where these videos are in more detail? Sometimes embedded videos are blocked by Firefox's Tracking Protection feature. By embedded videos I mean, for example, videos hosted on X, Instagram or TikTok that are displayed in a frame in the middle of an article, blog post, etc.

Also, in case you have an unbundled version of Windows, see: Fix video and audio problems on Firefox for Windows N editions.

They are always videos from news letters, videos embedded in them, or in the article the newsletter links to. Videos in X or Bluesky run just fine, these are always from a newspaper article. They run fine in other browsers. I run Windows Defender and Malwarebytes Pro as my security, this is relatively recent, they used to run fine, but it's been like this for several months.

I run Win 10 Pro, 16GB Ram, always updated, HP Pavilion desktop. Same videos will open on my iPhone or iPad Pro. I've not tried running in Troubleshoot Mode or Sandbox or anything like that. Don't use a VPN. I'm 76, retired, just running a basic desktop setup.

This is one such link: https://www.nbcnews.com/video/video-shows-kirk-shooting-crowd-dispersing-at-utah-event-247303749842 Same error code: Sorry, the video player failed to load.(Error Code: 104153)

You should also run this from HP. https://ftp.hp.com/pub/caps-softpaq/cmit/HPIA.html

You should also run this from HP. https://ftp.hp.com/pub/caps-softpaq/cmit/HPIA.html

That one's not supported on Win 10 22H2 or so it says, won't run.

Try here to check for drivers. https://support.hp.com/us-en/drivers/desktops

Windows Pro version, I would test in the Sandbox to confirm. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

Did you try the Windows update mentioned by J?

No shooting videos, please. How about golf?

https://www.nbcsports.com/watch/golf/dp-world-tour/dp-world-tour-highlights-2025-bmw-pga-championship-round-2?cid=nbcnews

That one doesn't play for me until I disable Tracking Protection (click the shield icon at the left end of the address bar next to the lock, then click the blue slider switch). But I don't know what exact site on the block list is affecting the video.

That one doesn't play for me until I disable Tracking Protection (click the shield icon at the left end of the address bar next to the lock, then click the blue slider switch). But I don't know what exact site on the block list is affecting the video.

Using a different tool to turn sites on/off, it looks like the video player calls a Scorecard Research script and if that is blocked, the video doesn't load. Very annoying: to watch, you must be counted.

Try here to check for drivers. https://support.hp.com/us-en/drivers/desktops Windows Pro version, I would test in the Sandbox to confirm. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/ Did you try the Windows update mentioned by J?

I did that didn't run. Did update a couple drivers and the BIOS though. I'll see if that helps.