Twitter uses a HTML5 player and not Flash.

You need to make sure you have packages like FFmpeg installed as Firefox has not used Gstreamer for a good while now.

You can check to see what your system supports at say https://www.youtube.com/html5/ as all check marks should be blue.

Still however even if you do fully support the HTML5 player the videos on Twitter can still annoyingly give this message sometimes instead of playing.

I just use chrome for the many different reasons videos won't play on Firefox.

I just use chrome for the many different reasons videos won't play on Firefox 57. Is there a plan for a massive fix to this new platform?

beatfarmer said

I just use chrome for the many different reasons videos won't play on Firefox 57. Is there a plan for a massive fix to this new platform?

Installing FFmpeg fixed all of my problems with media in FF.

I appreciate the help, but I'm baffled. Why is it that firefox has changed so much in the name of security, which requires us to download unknown zip files full of executables to fix the change? Why not just modify the browser so it plays videos like the other browsers do?

By the way, I refreshed firefox and I downloaded the windows media pack.

Twitter videos hosted on other websites may not work due to CSP violation errors. The Web Console should show an error message in such a case. You will have to click the link to open the video on the Twitter website.

• https://developer.mozilla.org/Security/CSP

cor-el said

Twitter videos hosted on other websites may not work due to CSP violation errors. The Web Console should show an error message in such a case. You will have to click the link to open the video on the Twitter website.

• https://developer.mozilla.org/Security/CSP

It seems that this is exactly the problem. When I'm trying to watch twitter videos on my favorite news website I get "The media could not be played", but if I open the video on the twitter website I can watch the video. This is quite annoying as I don't wish to switch websites all the time. Is there a way to insert websites into kind of a safe list so I won't have this issue? Is there any other solution? BTW, I can watch twitter videos on other websites in other browsers and this is only a firefox problem. Thanks

nadavamd said

this is only a firefox problem. Thanks

Edge on Windows 10 does the same so it is not necessarily a Firefox specific problem.

James said

nadavamd said

this is only a firefox problem. Thanks

Edge on Windows 10 does the same so it is not necessarily a Firefox specific problem.

I admit I didn't try Edge, but on Chrome it works just fine... In any case, I like using Firefox, and I'm trying to find a solution to this issue for Firefox.

cor-el said

Twitter videos hosted on other websites may not work due to CSP violation errors. The Web Console should show an error message in such a case. You will have to click the link to open the video on the Twitter website.

• https://developer.mozilla.org/Security/CSP

I don't want to bounce between websites just to view a video that every other browser plays just fine. It's ridiculous and aggravating as hell. Going to Twitter to play the video means I have to pause the video (because it autoplays), turn the sound on (because the default is off), resize to full-screen, move the progress bar back to the beginning (because I wasn't fast enough stopping the video when I got there), and then, finally, play the video. Great job, Mozilla. On recap pages (for NBA games) there might be 7-10 highlight videos, most under 30 seconds. This needs to be fixed/removed/whatever. Every other browser plays Twitter videos without having to go to Twitter. I don't care what or why CSP is. I just want my browser to WORK like it used to.

Now, anyone know which version of Firefox do I have to downgrade to in order to bypass this CSP crap?

Seapig said

I don't care what or why CSP is. I just want my browser to WORK like it used to.

Now, anyone know which version of Firefox do I have to downgrade to in order to bypass this CSP crap?

Changing your Firefox version won't help because Firefox has been following websites' CSP instructions for a long time.

You can turn off CSP -- Content Security Policy -- to allow the embedding videos to work. This suspends the feature web-wide; there is not a way to make an exception only for Twitter. At least not without an add-on of some kind.

Here's where you find that setting:

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

(2) In the search box above the list, type or paste csp and pause while the list is filtered

(3) Double-click the security.csp.enable preference to switch the value from true to false

If an affected page is already open, reload it (Windows: Ctrl+r, Mac: Command+r).

You may want to change the setting back when you're going to a previously unknown site.

Hopefully Twitter will fix their CSP instructions to resolve this issue.

Seapig said

Now, anyone know which version of Firefox do I have to downgrade to in order to bypass this CSP crap?

Considering that people say they have this same issue with embedded Twitter videos in Edge, it is not not necessarily a bug in recent Firefox versions.

It's Twitter that sets the rules for playing media hosted on their servers elsewhere. If other website host media files on Twitter and embed them on their web pages then they should check whether this is allowed. Twitter may have recently changed their CSP policy if this worked before.

A lot of websites for instance like this forum send an "X-Frame-Options: DENY" header that prevents opening files in a iframe. Others may have very strict CSP rules.