13 Replies Latest reply: Dec 16, 2012 10:41 AM by Courcoul
Chris Lappas Level 1 Level 1 (5 points)

I've only just noticed that some youtube videos like this one http://www.youtube.com/watch?feature=related&hl=el&v=jY2dcKvKWmI do not play on Safari anymore. It used to be fine and I have uninstalled no-flash and ad block which theoretically might have something to do with it, but without results.


I have even resorted to trashing the com.apple.safari.plist, but to no avail. Strange thing is that they play normally when embedded into other sites like facebook. Opera does not have any problem playing them whatsoever.


Any ideas?

MacBook Pro, Mac OS X (10.7.2), 15", 2,66GHz, Core 2 Duo, 8gb RAM
  • a brody Level 9 Level 9 (64,875 points)

    Install the latest version of Adobe Flash.

  • Chris Lappas Level 1 Level 1 (5 points)

    It was already installed and updated. In fact, I went so far as to remove flash completely using Adobe's official uninstaller and to then re-install it, but in vain. The problem persists.

  • Chris Lappas Level 1 Level 1 (5 points)

    Today -to my dismay- I noticed that even some of the videos I myself have uploaded on youtube refused to play.


    The culprit seems to be the safari plug-in "Perian". Whenever I deactivate it, all youtube videos play normally. Unfortunately, doing so means that QuickTime can no longer play certain files, such as .flv


    Perian has a tab in System Preferences, but the options are not relevant to the problem with safari.

  • Andy Drefs Level 1 Level 1 (5 points)

    I'm having the same issue...

  • Baby Boomer (USofA) Level 9 Level 9 (56,970 points)

    Andy Drefs wrote:


    I'm having the same issue...


    It's generally better to start your own Topic, rather than adding onto an existing one that's been dead for months. 

    Please start a new topic about your issue so it can receive more focused attention.


    In order for us to give your problem our undivided attention in order to try to solve it, would you kindly describe the trouble you are having in the fullest detail, including completing your details to show what Mac you are using, what operating system, and what version of the application in question.



    Thank you!
















  • Andy Drefs Level 1 Level 1 (5 points)

    And just who the heck are you, Baby Boomer?  Is large RED all BOLD font really necessary?  Is "I'm having the same issue"  that difficult to discern?  I have a Mac Pro tower, Lion 10.7.3 and Safari 5.1.3


    And I'm having the exact same issues as those listed by Chris Lappas.  Dead for months?  How so?  I don't see that he's gotten any resolution since waaaayyyyyyy back at the end of 2011, if one can even think back that far.

  • Chris Lappas Level 1 Level 1 (5 points)



    The cause of my problem was strange. I had selected for YouTube videos to play by HTML rather than Flash (somewhere in the youtube page there was this option). Once I switched the setting back to Flash, all problems disappeared and videos play normally irrespective of my installed pluggins.

  • Andy Drefs Level 1 Level 1 (5 points)

    That is strange Chris since I haven't done anything with those settings nor do I even know where to find them (and I just looked).  If I open the same pages with Chrome all vids play fine, in Safari, nada.

  • Chris Lappas Level 1 Level 1 (5 points)



    Check if yours is active. If it is, you might want to deactivate it.

  • HevvyRevvy Level 1 Level 1 (0 points)

    Thank you, Chris, for the clarification and the link.  If I may add just a little more clarification: if at any time you elected to participate in the HTML5 trial on YouTube, some of your videos will not play. Why? Because at this time, those videos with ads "are not supported". Also, if you've opted into any other "testtube" experiments, the HTML5 player may not show up (http://www.youtube.com/html5: Additional Restrictions).  According to the link Chris provided, this is something that is being worked on but if Google is true to form, it's probably going to take a while - though since it's affecting their revenue stream, maybe not...


    With respect to Andy's complaint about BabyBoomer's comment, I found the use of large red, all bold letters annoying and rude as well. If it's a formatting issue that's one thing but if it was a deliberate attempt to intimidate or otherwise show some kind of superiority - which is how it comes across - then that's not very professional or helpful. It was kind of Chris to come back and explain how he overcame his problem.





  • HevvyRevvy Level 1 Level 1 (0 points)

    Since posting my reply above a little over an hour ago, I found more information here on the forums, though I don't remember which thread or who posted the answer. Sorry .  Anyway, once you've disabled the html5 trial on youtube.com, you may discover that Safari won't play any youtube videos. Don't panic. Simply go into your Safari browser's Preferences, then into the Privacy section. There you'll see a button (under Cookies and other website data) to 'Remove All Website Data'. Under that button you'll see a list of the number of website cookies and other data stored and next to that is a 'Details' button. Click the 'Details' button to open the list. Scroll down to YouTube and highlight it. Next, click on the 'Remove' button to remove just the YouTube data or the 'Remove All' button to remove all of the stored tracking data. Once you've finished, click on the 'Done' button and close the Preferences window. 


    Once you've cleared the youtube data, refresh whatever video page you were on to once again be able to see video.  I even went so far as to re-enable youtube's html5 trial. I want to see if videos will stop playing again so I know whether or not to disable the trial completely. 


    Hope this helps!



  • RichCo Level 1 Level 1 (10 points)

    I'm not sure if this discussion is still active but I wanted to report and thank Chris Lappas on his HTML explanation and also on the link he provided to check it out. I just began to experience this problem in December and never was asked by Youtube if I wanted to participate in any trial.


    When some videos would not play, I began researching Youtube's site but I was not able to find anything that addressed the problem. So I checked the forums and clicked on Chris's link and unchecked the HTML trial button and now everything is back to normal. 


    These apple discussion forums are invaluable.

  • Courcoul Level 6 Level 6 (12,555 points)

    And to add my two penny's worth, note that after the big virus/trojan issue Apple had back in early 2012 due to third party add ons besmirching the Lion's good name, running outdated versions of Flash and Java will cause the system to disable the plugins.


    While this probably won't be an issue here, it may prove to be the stumbling block with other less savvy users that have similar issues and happen to come across this thread.