Mozilla Software → FF 57.0.2 Embedded Twitter videos won't play

The past couple of days (since update to 57.0.2) I have not been able to play videos in embedded Twitter feeds in DSLR. I get the message "The media could not be played". I can play the videos in other browsers and can play them on the Twitter page. I have set media.mediasource.webm.enabled to true. Visiting »www.youtube.com/html5/ shows all checked. This is both on my PC and tablet both running Win 10. Any suggestions?

Example page/video with the issue?

»twitter.com/SkyNews/stat ··· 32717056

If you go to about:config and set security.csp.enable to false then they will play here.

Content Security Policy: The page’s settings blocked the loading of a resource at self (“script-src 'unsafe-eval' https://twitter.com http://localhost:* http://localhost.twitter.com:* https://*.twitter.com https://*.twimg.com https://vine.co https://*.vine.co https://*.periscope.tv https://*.pscp.tv”). Source: onfocusin attribute on DIV element.
882509461532717056
Content Security Policy: The page’s settings blocked the loading of a resource at blob:https://twitter.com/64f5e1dc-5301-49c8-bbde-8ff8b0f6f117 (“default-src https://twitter.com http://localhost:* http://localhost.twitter.com:* https://*.twitter.com https://*.twimg.com https://vine.co https://*.vine.co https://*.periscope.tv https://*.pscp.tv”).
 

So, looks like it's how the DSLR site is configured.

Worked. Thanks!

I have the same problem too! So it's the way websites are configured not working with FF 57.0.2? Must be a bug in firefox then?

Thanks MarkRH .... had the same issue as well.

Do note, fwiw, (& I know that you know), that Content Security Policy (CSP) is there for security reasons. So do realize that by disabling CSP you lessen security, so if tweats (or whatever) are so important, you may want to disable, then re-enable rather then disabling & forgetting about it.

When available, like here, you can open the link (instead of "playing" the embed) & that should work without having to juggle CSP.