This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

HTML5 videos will not playback

  • 7 respostas
  • 1 has this problem
  • 1 view
  • Last reply by 14woody7yar

more options

All of a sudden, most of the videos on any site will not playback. From the Adobe Flash troubleshooting page, it appears that it is the HTML5 videos that will not play. When I clicked on the test for Non-HTML5 videos, it played back fine. Watched CBS web site one night, next day, nothing plays. Same with Youtube, ABC, NBC, yahoo news, cnn, etc. They all look like they are loading and getting ready to play, but the circle just keeps spinning, and then I get a message that says if playback does not start soon, I should restart my device. Restarting the device (my PC) does nothing. I have uninstalled, and reinstalled both Firefox and Flash. I have also refreshed Firefox. Nothing works. And all the videos will play on Edge and Chrome, so I know it has to be something with either Firefox or with Firefox and my PC together. How do I get videos to play again in Firefox?

All of a sudden, most of the videos on any site will not playback. From the Adobe Flash troubleshooting page, it appears that it is the HTML5 videos that will not play. When I clicked on the test for Non-HTML5 videos, it played back fine. Watched CBS web site one night, next day, nothing plays. Same with Youtube, ABC, NBC, yahoo news, cnn, etc. They all look like they are loading and getting ready to play, but the circle just keeps spinning, and then I get a message that says if playback does not start soon, I should restart my device. Restarting the device (my PC) does nothing. I have uninstalled, and reinstalled both Firefox and Flash. I have also refreshed Firefox. Nothing works. And all the videos will play on Edge and Chrome, so I know it has to be something with either Firefox or with Firefox and my PC together. How do I get videos to play again in Firefox?

All Replies (7)

more options

If you check YouTube's diagnostic page, do you have red boxes?

https://www.youtube.com/html5

Not sure if anything in this article is helpful: Fix video and audio problems on Firefox for Windows N editions.

Do you use any programs that are supposed to record or download videos?

more options

I do have a red box with an exclamation mark (!) in it on the MSE & WebM VP9 box. I don't typically watch youtube, and I don't know how to change that, or if that is the problem. I only went to youtube to see if I had the same non-playback problem with videos.

Nothing in that article was helpful for me. Not sure if because it did not address my problem, or because I did not understand some of what it was saying.

I don't know if I have any programs to record or download videos, but if I do, I do not use them.

more options

spleeff39 said

I do have a red box with an exclamation mark (!) in it on the MSE & WebM VP9 box. I don't typically watch youtube, and I don't know how to change that, or if that is the problem.

VP9 is rarely used except by Google.

Since everything is detected as supported by Firefox, the results you're getting from actual players are puzzling.

Could Tracking Protection be a factor? When Firefox's Tracking Protection feature is blocking content in a page, a shield icon appears at the left end of the address bar. More info in this article: What happened to Tracking Protection?.

more options

You can check the Web Console (Tools -> Web Developer) for messages about blocked content and about the presence of mixed or unsafe content.

You can check the Network Monitor to see if content is blocked or otherwise fails to load.

If necessary use "Ctrl+F5" or "Ctrl+Shift+R" (Mac: Command+Shift+R) to reload the page and bypass the cache to generate a fresh log.

more options

Ok, when I go to the web console, I do get a couple of Red Alert type messages, but I have no idea what they mean or how to fix them. The first messages state: Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://pmp.ybp.yahoo.com/bid/yoo/adslot/144/?n=[timestamp&vi_ct=&vpaidt=&vpaidv=]. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Loading failed for the <script> with source “https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js”. r-sf.html:35 Loading failed for the <script> with source “https://js-agent.newrelic.com/nr-1071.min.js”. Then the ones in red, with what looks like a triangular alert type symbol says: XML Parsing Error: no root element found Location: https://t2.hulu.com/qos/playback?cb=1517365658208_906 Line Number 1, Column 1: playback:1:1 Ad errored out ERR_MEDIA_PLAYBACK Then the final note, in regular black font on white background states: Permission denied to access property "document" on cross-origin object ca:23:100 I am sorry, but while I know a how figure out some basic stuff, I am not a programmer or coder, or developer, and, while I can tell these are telling me there is some problems, I do not understand any of the information. Thank you for taking the time to try to help. I will check the Network Monitor now.

more options

Did not see the earlier suggestion from Jscher2000. I turned off tracking protection, but it did not change anything. Still won't play. Funny thing is it worked fine the night before it didn't. Went to bed, and when I got up the next day and went online, it wouldn't work. Firefox did do an automatic update, but they did that on my laptop also, and it all works fine on the laptop.

more options

'I found this solution in another feed. It seems to have solved my problem with the streaming video issue.


Chosen solution

Another thing to try : Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

You will need to restart Firefox for this to take effect so save all work first (e.g., mail you are composing, online documents you're editing, etc.,) and then perform these steps:

In Firefox 54 and below:

  Click the menu button New Fx Menu and select Options (Windows) or Preferences (Mac, Linux).
  Select the Advanced panel and the General tab.
  Uncheck Use hardware acceleration when available.
  Close Firefox completely and then restart Firefox to see if the problem persists. 

In Firefox 55 and above:

  Click the menu button New Fx Menu and select Options (Windows) or Preferences (Mac, Linux).
  Select the General panel.
  Under Performance, uncheck Use recommended performance settings. Additional settings will be displayed.
  Fx55Performance-disableHWA
  Uncheck Use hardware acceleration when available.
  Close Firefox completely and then restart Firefox to see if the problem persists. 

Did this fix your problems? Please report back to us!

If the problem is resolved, you should check for updates for your graphics driver by following the steps mentioned in these Knowledge base articles:

  Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems 
  Upgrade your graphics drivers to use hardware acceleration and Web