Updated Firefox to the most recent version, this is still a problem.

I'm at my wits end with this. I have a lot invested in the Mozilla ecosystem and using a different browser on this one computer is highly inconvenient.

Is there a specific error message in the player area?

What results do you get on the following diagnostic page that tests for feature support (my copy of the old YouTube HTML5 support page):

https://www.jeffersonscher.com/sumo/html5-video.html

What you would normally expect to see is:

There's no specific error message on YouTube. All that happens is the circle in the center of the video spins and the page looks like it's loading the video - like it's buffering - but never starts playing.

On Twitter it behaves the same... every website is the same; video looks like it's buffering but never loads. Doesn't matter what site it's on and the only problem I continue to have is with videos. Pages and images load normally.

I went to that site you linked and it looks just like your post (I attached a screen grab).

Thank you for your time. My apologies for the late response.

Is there a specific error message in the player area? What results do you get on the following diagnostic page that tests for feature support (my copy of the old YouTube HTML5 support page): https://www.jeffersonscher.com/sumo/html5-video.html What you would normally expect to see is:

I didn't know how to quote before. Just wanted to ping you in case you miss my late response.

A link to the video at issue would help others compare what if the issue you see or get compares to what they get as well. This is what I get for my test. Also on you "Things I ...." . There is no listing of Disabling all Addons as well. So if you not doing this this could be the very source of the problems. There are two types for FireFox Addons section and Extension section. And did you try Chrome as well since it's Google and Youtube is Google one needs to try different Browser for comparisons to see what is happening here.

In both my posts I mention already that the problem is with every single video from every single source. It isn't a single site or video in question.

I also mentioned that videos play fine in Chrome, Opera, Edge, and Brave. So I have indeed tried other browsers. The issue is exclusive to FireFox.

As for disabling add-ons, see "Things I've Tried" 10, 11, and 12.

Thank you for your response.

Thank you for checking that.

In another thread, a user mentioned a similar issue, which potentially was related to the auto-play block. If you were to manually pause/resume the video, that should bypass the block, so you probably have ruled that out already but you could turn it off just in case: Allow or block media autoplay in Firefox.

Do you recall what this is about:

What finally worked back in April was to dive into "about:config" and change "media.rdd-process.enabled" to "false". That fix does not work this time around.

I think RDD refers to a separate process for media decoding, but I'm not familiar with the details of any compatibility or configuration issues that could cause inter-process communication failure.

Thank you for the quick response!

In another thread, a user mentioned a similar issue, which potentially was related to the auto-play block. If you were to manually pause/resume the video, that should bypass the block, so you probably have ruled that out already but you could turn it off just in case: Allow or block media autoplay in Firefox.

I checked that and it's set to allow everything. I attached an image to show.

Do you recall what this is about:

What finally worked back in April was to dive into "about:config" and change "media.rdd-process.enabled" to "false". That fix does not work this time around.

jscher2000 - Support Volunteer said

I think RDD refers to a separate process for media decoding, but I'm not familiar with the details of any compatibility or configuration issues that could cause inter-process communication failure.

I'm not sure what that particular instruction was meant to do, I'm not too familiar with that config setting. But I changed it earlier this year following instructions I found someplace on here and it worked then, but it no longer works now unfortunately. I've added a pic to show the setting, too.

The last image I've attached is of what it looks like for a YT video to play - or not play as it were. It shows that it's buffered and I even see thumbnails when I hover over the timeline in the video. It just won't play.

Edit: I realize that the video in the YT screenshot is "paused" according to the controls, but I had just gotten done attempting to pause and play per the suggestion. No dice.

In case it uses a different code path than MP4, any difference with WebM or OGV video?

• https://en.wikipedia.org/wiki/File:Big_Buck_Bunny_4K.webm
• https://commons.wikimedia.org/wiki/File:Examplevideo.ogv

Nope, same issue on both of those.

My last hope would be some kind of message in the web console. Ctrl+Shift+K to open that panel in the lower part of the tab, then reload the page and check for initial stuff. Then try to play the video and see whether anything new appears.

Here's what I get.

Looks like mostly "Information" items that wouldn't explain a stopped player. If you check for messages on one of the simpler sites or with a bare MP4 or WebM file, is there anything else?

When I look for threads about the Referrer policy message, I found mention of needing to add a trusted site in Ghostery, but that would only be relevant in normal mode, not in Troubleshoot Mode (extensions disabled).

https://www.reddit.com/r/firefox/comments/vo4yyh/cant_load_reddit_anymore_from_firefox/

When I look for threads about the Referrer policy message, I found mention of needing to add a trusted site in Ghostery, but that would only be relevant in normal mode, not in Troubleshoot Mode (extensions disabled). https://www.reddit.com/r/firefox/comments/vo4yyh/cant_load_reddit_anymore_from_firefox/

Looks like mostly "Information" items that wouldn't explain a stopped player. If you check for messages on one of the simpler sites or with a bare MP4 or WebM file, is there anything else?

Ok, so I went to this file: https://dl8.webmfiles.org/big-buck-bunny_trailer.webm

Trusted the site on Ghostery and tried to play the file from Firefox and I the only message in the console is listed in the image I've attached.

I'm puzzled by this error:

"The fetching process for the media resource was aborted by the user agent at the user's request."

It would be difficult to cancel the request quickly enough for it actually to be at your request. Maybe this refers to a configuration option. In trying to follow the source code, it also seems it might be used if there is a decoding problem or maybe a buffering problem.

If it is decoding, that would like up with your earlier reference to "rdd".

Can you file a bug at https://bugzilla.mozilla.org/ where hopefully someone more familiar with the internals can figure it out.

A Firefox 102 user appears to be reporting the same or similar issue: https://support.mozilla.org/questions/1390122

I'm puzzled by this error: "The fetching process for the media resource was aborted by the user agent at the user's request." It would be difficult to cancel the request quickly enough for it actually to be at your request. Maybe this refers to a configuration option. In trying to follow the source code, it also seems it might be used if there is a decoding problem or maybe a buffering problem. If it is decoding, that would like up with your earlier reference to "rdd". Can you file a bug at https://bugzilla.mozilla.org/ where hopefully someone more familiar with the internals can figure it out. A Firefox 102 user appears to be reporting the same or similar issue: https://support.mozilla.org/questions/1390122

Will do!

Thank you for all your help. I really appreciate your time and detailed responses.

Have a great week!

Hello there. browser.launcherProcess.enabled set to false has solved the issue for us, apparently, though I don't know what it does.

Hello there. browser.launcherProcess.enabled set to false has solved the issue for us, apparently, though I don't know what it does.

No dice. Thank you for the suggestion though!

The problem persists. So, short of re-installing Windows I think it's time to give up and deal.

Thank you for your time and help, everyone!

Hey there, back again with some more.

Have you tried launching a profile in a new browser from about:profiles ?

Lastly, it seems it also works when I put firefox.exe in compatibility mode for Windows 8. I still can't find the root of this issue but I keep searching...