A few days ago, this problem appeared. When I play a Youtube video, I get sound but no picture, only black screen. It is a HTML5 video.

I have turned off all related addons, and the problem is still present.

What can cause this?

These are my specs:

HP G5 255 (laptop); 15,6 inch 1080p display; AMD A6-7310 APU with AMD Radeon R4 Graphics × 4 (1 GB allocated to iGPU) Gallium 0.4 on AMD MULLINS (DRM 2.49.0 / 4.10.10-041010-generic, LLVM 4.0.1), Mesa 17.2-dev; 12 GB DDR3L 1600 MHz (4 + 8 GB); Ubuntu 16.04 64-bit; Firefox 53.0.3 (64-bit)

  • Could you display the results from youtube.com/html5 ?
    – user3169
    Jun 18, 2017 at 5:37
  • Yes, everything is good regarding that, but I still have a black screen. s4.postimg.org/wlhb419rx/HTML5.png Jun 18, 2017 at 14:14
  • 1
    How about in FF safe mode? I guess the other question would be what else changed "a few days ago". Also FF54 should be available (it was here a couple of days ago).
    – user3169
    Jun 18, 2017 at 16:24
  • Well, I have no idea what happened. But I have turned of Firefox, turned it on in safe mode and the Youtube worked fine (no blackscreen). Then I closed it, opene it up in normal mode, and Youtube works fine again. Thank you for your help. Jun 18, 2017 at 20:18
  • Once you are satisfied that the problem is fixed, you should write an answer saying that this fixed it (it is OK to answer your own question). My guess is that some extension or plugin may have been temporarily messed up. So keep an eye on them.
    – user3169
    Jun 18, 2017 at 20:22

1 Answer 1


It has been fixed by these steps:

  • Closing Firefox
  • Starting Firefox in Safe Mode
  • Closing it
  • Starting Firefox in normal mode

Simply restarting (closing and starting) Firefox in normal mode had no effect.

Edit: I have just noticed that Firefox is now updated to version 54. Maybe that fixed it. But I don't remebmer getting any FIrefox updates, nor did I get any notification to restart FIrefox in order to update.

  • Update 2 in this answer may provide a clue about why this worked.
    – karel
    Jun 19, 2017 at 7:52

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