Firefox does not play youtube videos after some time
This is an older issue of mine. Firefox - of course - plays youtube videos without problems in general. However after some usage (eg many hours of usage, many videos watched, etc, regardless it's a video embedded in pages or on youtube.com directly) it only shows the circulating dots and video is not started. Again, it happens after some use, not at the start up of the browser. To be more interesting, if I try to exit from browser right after having this problem I can't restart Firefox as it says it's already running. And that's true, from a terminal window (I use Linux only) I can see that Firefox process is there using some CPU time, usually between 40% and 60%. If I kill firefox process with the "kill" command, I can start Firefox again, and the problematic video plays without any issue at all! Just it's a bit annoying that I have to restart Firefox to be able to watch a given video, and also a terminal window action is needed to be able to kill the Firefox process to be able to restart Firefox ...
I use Firefox 41.0.2 (but the problem existed in older versions as well) on 32 bit Linux system, Ubuntu 15.10 (again, the problem could be noticed in older Ubuntu versions as well).
Opaite Mbohovái (3)
I'm sorry, I forgot to mention that if I try to exit after having the problem, it seems firefox exists, ie its window disappears. Just I know it is still running as a process as restarting does not work and firefox reports already running, and also I can see the firefox process running from command line.
That could be a memory problem with the HTML5 media player where the player doesn't unload properly.
You could try to force a Flash based player to see if the Flash player doesn't have this issue.
You can use an extension to switch between the Flash player and the HTML5 media player on the YouTube website. YouTube Flash Video Player:
Thanks for your answer, however I would like to forget flash if it's possible because various reasons including that I'm also a big fan of HTML5 over plugin-like technologies :) If it's a known problem (of firefox?, or should I report somewhere else too?) is there any hope for the fix some time? As it seems everybody would like kill flash, and also youtube urges to use html5, I think it's more important to fix the html5-capable features and not to "downgrade" the user experience to "older" technology. Anyway thanks for the tip, if no better short-term solution exists, I may use your useful advice.