Hello,

kertase wrote:

Since the update to Firefox 28 some videos for example http://www.youtube.com/watch?v=XSGBVzeBUbk will not play. Also the page does not finish loading...

That plays fine for me in HTML5 WebM format, if I disable Flash Player. Try clearing the cache and deleting cookies from youtube.com and ytimg.com.

• How to clear the Firefox cache
• Clear cookies and site data in Firefox

Alternatively, I can play it in HTML5 MP4 format with the following add-on. Under Linux playing this format depends on some additional packages being installed (gstreamer, gst-plugins-base, gst-plugins-good, gst-plugins-bad and either gst-libav or a third-party H.264 decoder like Fluendo).

• https://addons.mozilla.org/firefox/addon/youtube-all-html5/

kertase wrote:

What seems to be weird is that hd1080 is available now.

I can only get a 1080p version if Flash Player is enabled. YouTube limits 1080p to Flash Player and browsers that support MPEG-DASH (notably Chrome).

kertase wrote:

Maybe something does not work correctly with "MSE"?

What you mean by MSE? Are you referring to Microsoft Security Essentials? It looks like you're posting from Linux. Why would a Windows-only product affect you?

kertase wrote:

Flashplayer is not a solution since it is not available for me. 

How so? Flash Player available for all platforms.

• Install the Flash plugin to view videos, animations and games

Ok I have cleared cache files and cookies but it did not solve the problem.

I have the needed packages installed for mp4 (and it worked before updating firefox).

MSE (Media source extension) includes DASH but is disabled in firefox so it should not be the reason... but since 1080p is available in youtube maybe something is wrong there...

Works with me on Linux with both the Flash player (max: HD 1080) and the HTML5 media player (max: HD 720).

• http://www.youtube.com/watch?v=XSGBVzeBUbk&html5=1

Seems really weird... retried removing cash and cookies and checked some options but still does not work.

Here an screenshot just in case...

And a few minutes later still loading...

Hum... Youtube seems to have DASH enabled (second screenshot) but firefox should not support it, or does it?

kertase wrote:

Here an screenshot just in case...

The missing thumbnails on the right side of the page suggest blocked content from either youtube.com or ytimg.com. Click the Adblock Plus icon on the toolbar and choose Disable Everywhere, then reload the page.

If that solves the problem, troubleshoot filter issues in Adblock Plus as follows:

1. Update your filter lists manually.
   • https://adblockplus.org/en/faq_basics#update-filterlists
2. Check for faulty custom filters.
   • https://support.mozilla.org/questions/990448#answer-545088

Hi everyone,

Randomly worked for a while but is back now...

Adblockplus does not seem to be the source of the problem.