Endpoints... Are you at work or home? It works for me. see screenshot Show us the issue, what are you seeing?

Hello jonzn, thanks for the answer. I'm currently on site, our users report the same issue xorking from home, with our without VPN.

It's really linked to Firefox ESR 102.

Attached is a screenshot of the youtube player. This is all we get, "nothing". This is with or without adblocker, too (only extension installed).

What's weird is the video does preload and I can see the thumbnail if I mouse over the timeline. It just never starts. No media content, sound or video, ever starts.

I tried the console but I don't really know how to interpret it. Mostly I see lots and lots of lines about "origin-when-cross-origin" strategy or "no-referrer-when-downgrade" strategy depending on the site used.

I'm trying to figure out what might have changed with ESR 102 that could cause this.

• Network issue ?
• GPO issue ?
• Prefs issue ?

Best regards,

sniff sniff... I smell GPO issues. I assume you or your users already tested the issue on a personal computer, not work related computer. I have the browser in Windows, Linux, and Mac with no issue.

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

This could be related to an issue reported by other users of Google sites linked to the "zero round trip resumption" feature. Another symptom is "Oops" messages about a lost connection on Gmail. You can disable this feature and test whether it helps:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste security.tls.enable_0rtt_data and pause while the list is filtered

(3) Double-click the preference to switch the value from true to false

After that, try Google or YouTube again. Any improvement?

Hello guys, and thank you for the feedback.

Sadly Cor-El, the issue remains with a new profile. I attempted removing all data from Firefox and trying again, but it gave the same result. Troubleshoot mode gave the same result, that's why I thought it might be a GPO issue.

But we had the same issue on a non-GPO computer, so it's tough to say.

Jscher2000, yes I had found that and tried it too, sadly it doesn't seem to be security.tls.enable_0rtt_data.

I found several threads that might be linked to this like security.fileuri.strict_origin_policy and some tracking options, but it doesn't seem to be it. At this point I'm trying everything remotely connected to the issue, false and true, and see what that gives...=(

Best regards,

I don't suppose hitting pause and then hitting play makes any difference? In an early iteration of the autoplay block, that was sometimes necessary.

Assuming, not:

You could check the Developer Tools panel to see whether there are any relevant error messages. The Web Console (Ctrl+Shift+K) should show those.

Indeed, pausing and resuming the video doesn't change anything, it doesn't load.

I've been trying to use the console to find out what might be wrong, but so far it hasn't really helped, as I don't really know what to look for in the logs.

The error I get through the console is that a cross-origin request has been blocked because of the "same origin" policy (CORS request failure). I'm still trying to find a setting about that =(...

Best regards,

Any relevant-looking media messages in the Web Console?

• https://developer.mozilla.org/en-US/docs/Tools/Web_Console

With the dev tools open, you also could click over to the Network panel, then reload the page in the upper part of the tab and watch for the requests to other sites (especially subdomains of googlevideo.com) and see whether those are successful.

As far as network logs go, there are no errors with GET/POST methods (as long as I keep the adblock off).

As for media related messages in the console, I'm really not sure what to look for, there's nothing specific about media in there.

I get a few warnings (cookies, content security policy), several errors "Uncaught": Uncaught 7 5k7CCto5.html:11:866

   Ha https://tpc.googlesyndication.com/sodar/5k7CCto5.html:11
   (Asynchrone : setTimeout handler)
   Ha https://tpc.googlesyndication.com/sodar/5k7CCto5.html:11
   eb https://tpc.googlesyndication.com/sodar/5k7CCto5.html:20
   Qa https://tpc.googlesyndication.com/sodar/5k7CCto5.html:13

And tons (60) of "information", all of which are referrer policy less restrictive "origin-when-cross-origin" ignored for cross-site request.

Have a nice start of your week =) !

Best regards,

Puzzling. It sounds like connection is not the issue.

If you hold the shift key and right-click the player (this bypasses Google's custom context menu), does the video section of the menu show "Pause" -- as though Firefox thinks it is playing the video -- or "Play" -- as though Firefox has paused the video?

Can an MP4 play in Firefox's stand-alone viewer? That's the viewer that runs when you open an MP4 file in its own tab.

It shows "Pause".

When I try to read a local mp4 file in Firefox, it acts the ame way, it displays the player, but never starts.

I confirmed the file worked in VLC.

Sadly, I get nothing in the debug console when I try to read MP4 files in Firefox =(...

Thank you for checking that. In the following thread, the video has loaded and thumbnails are available when you mouse along the play bar on YouTube, but the player will not start:

https://support.mozilla.org/questions/1384191

Does that at all sound like what you are seeing?

Thank you for checking that. In the following thread, the video has loaded and thumbnails are available when you mouse along the play bar on YouTube, but the player will not start: https://support.mozilla.org/questions/1384191 Does that at all sound like what you are seeing?

Yep, pretty much, at least it would be highly surprising if it wasn't the same issue. Glad to see I'm not alone in this, not that it helps us move forward ; ; ...

Best regards,

I'm stumped. I tried Firefox standard (non-ESR) and it doesn't work either. From your answers on the other post, I get the normal answer to the legacy youtube html 5 video test page (see attached).

I tried playing the example videos from the wiki, I get the following logs in the console:

Stratégie de référent : la stratégie de référent la moins restrictive « origin-when-cross-origin » est ignorée pour la requête intersite : https://upload.wikimedia.org/wikipedia/commons/transcoded/c/c0/Big_Buck_Bunny_4K.webm/Big_Buck_Bunny_4K.webm.480p.webm Big_Buck_Bunny_4K.webm.480p.webm GEThttps://upload.wikimedia.org/wikipedia/commons/transcoded/c/c0/Big_Buck_Bunny_4K.webm/Big_Buck_Bunny_4K.webm.480p.webm

Stratégie de référent : la stratégie de référent la moins restrictive « origin-when-cross-origin » est ignorée pour la requête intersite : https://upload.wikimedia.org/wikipedia/commons/transcoded/c/c0/Big_Buck_Bunny_4K.webm/Big_Buck_Bunny_4K.webm.720p.webm Big_Buck_Bunny_4K.webm.720p.webm GEThttps://upload.wikimedia.org/wikipedia/commons/transcoded/c/c0/Big_Buck_Bunny_4K.webm/Big_Buck_Bunny_4K.webm.720p.webm

Can't find the exact translation, but apparently this would be something like : Referrer policy : Less restrictive policy "origin-when-cross-origin" is ignored for cross-site request: https://...

I'm getting lost amongst cors, headers, cross-origin, samesite, tracking...I've seen so many things and I'm no closer to finding out what setting is new and specific to Firefox 100+ that's conflicting with this...

Best regards,

Firefox 78 ESR is the last version of Firefox that supports Flash. The last version of that ESR will be 78.15, which is scheduled to be released on 2021-10-05. This means that Flash will officially be out of support on Firefox when Firefox 78 ESR reaches EOL.

If the standard version you tested was 105, I'm not surprised it behaves more like 102 than 91. Hmm...

When I look for threads about the Referrer policy message, I found mention of needing to add a trusted site in Ghostery. Could Ghostery or another add-ons that modifies requests be a factor?

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

But I get those informational messages about referrer policy and can play the videos normally, so I don't think that is leading us to a solution.

Can you show a screenshot of the Web Console (maybe clear the console before starting a video) ?

Did you already try to reboot the computer in Windows Troubleshoot Mode ?

Boot the computer in Windows Safe Mode with network support to see if that has effect.

• https://www.bleepingcomputer.com/tuto.../how-to-start-windows-in-safe-mode/
• https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10/