Firefox crashes in Ubuntu on flash content

Problem: Firefox on Ubuntu is crashing when it encounters flash content. Solution: Uninstall the libflash0c2 package.


Mozilla Firefox on Ubuntu Linux (Dapper Drake) was crashing every time it encountered a page with Macromedia Shockwave or Macromedia Flash. The crash produced this error in the terminal:

The program 'Gecko' received an X Window System error.
This probably reflects a bug in the program.

A look into the about:plugins page in Firefox showed an anomaly: there appeared to be be two plugins handling flash content.

Additionally, trying to use the standalone flash viewer swfplayer also resulted in a crash.

Synaptic package manager revealed that several flash plugins were installed. The libflash0c2 library package and two dependants (libflash-mozplugin and libflash-swfplayer, the crashing plugin and application) seemed to be the source of the trouble. flashplayer-mozilla was also installed.


The libflash0c2 seems to be the source of the problem, and uninstalling it and its dependants appears to solve this particular flash-Firefox problem.

  1. Close all Mozilla-family browser windows (Mozilla, Firefox, Galeon, Epiphany, etc.)
  2. Uninstall libflash0c2 using Synaptic package manager or apt.

Bonus: Jim Caya posted another solution in the comments below. You might try either my solution or his and see if it works instead of doing both -- and I'd be interested to hear back from folks on what combinations work or don't work.

Either the two flash plugins were conflicting or there is a bug in the libflash0c2 library. There are other flash-Firefox and flash-Ubuntu problems involving sound, and solutions can be located on the site.

Responses: 22 so far Feed icon

  1. Stuardo -StR- Rodríguez says:

    Ok, I uninstalled the following packages:

    p libflash-dev - GPL Flash (SWF) Library - development files p libflash-mozplugin - GPL Flash (SWF) Library - Mozilla-compatible p libflash-swfplayer - GPL Flash (SWF) Library - stand-alone player p libflash0c2 - GPL Flash (SWF) Library - shared library

    after that.... I cannot see any flash with Firefox. and if I install the flash via Firefox, firefox will crash again. So, for now it is not posible to view flash in dapper.

  2. Tim McCormack says:

    So, try just installing flashplayer-mozilla, and let me know what happens (whether it works or not.)

    I don't know what happens when you try to install flash from within Firefox -- might be asking for trouble.

  3. Stuardo -StR- Rodríguez says:

    nothing, the same crash that package, the macromedia/adobe plugin, everything.. it just crash

  4. Tim McCormack says:

    Do you get the same error? What happens if you swap flashplayer-mozilla for flashplayer-nonfree?

  5. cbonar says:

    I've exactly the same problem : firefox crashes as soon as I open a page with flash.

    I'm using Kubuntu on a Dell laptop.

    I tried all recepies I could find on the net, uninstalling every package with 'flash' in the name before, like : installing flashplugin-nonfree (which is I guess just the same as using Macromedia's installer), installing the gpl version (that does not work at all, actually), installing all known dependencies (even far ones), etc. Nothing changed.

    Yesterday I tried the previous version of the plugin in macromedia's releases and it's the same so it seems it doesn't come from the plugin itself. More, it doesnt' crash in konqueror (although I miss the video part).

    I think some installed component somewhere messes the whole thing up, but which one... I don't remember having this problem in my previous ubuntu and xubuntu installations.

    Did you solve this problem ?

  6. cbonar says:

    ...and.... I did uninstall libflash0c2 with no success.

  7. Tim McCormack says:

    You might try checking the about:plugins page in Firefox to make sure that there aren't multiple plugins trying to handle Flash or Shockwave content. Other than that, I'm at a loss.

    If you do find a solution that isn't mentioned here, I'd appreciate it if you would leave a comment about it. Others might be having the same problem. I was able to solve it on my system (though I still have Flash-related sound problems), but the symptoms your system is displaying might have a different origin.

    Good luck!

  8. cbonar says:

    I've already checked that before (recommended here and in other sites) : only one plugin.

    Anyway I solved this problem, but still I'm not totally sure what worked.

    I've downloaded and overwritten /usr/lib/firefox with the same version of firefox from mozilla's ftp, but localized for france (indeed it's my location but I don't have knowledge of any component in my ubuntu set for french, distro included... huh)... I then installed the flash plugin from macromedia's installer. It just worked. Google video, flash animations... the whole stuff !

    After that I discovered I had another plugin installed that was not there before : I don't know from where it comes from ; either ffox or flash (and I don't wanna know as long as it works :).

    Anyway, here I am : Firefox + flash 7.0 r63 !

    Thanks for the tips ; nice site by the way.

  9. Tim McCormack says:

    Well, I'm glad you've gotten it to work, even if it's by magic. :-S

    Incidentally, there is a localization package for french: mozilla-firefox-locale-fr-fr. Of course, you may not want to disturb your current configuration.

    Apparantly, handles missing plugins -- that is, it produces that "click here to download plugin" box where an object would normally be. I'll have to poke at that and see what bearing it might have on the situation. Very interesting, and thanks for writing back!

  10. cbonar says:

    I forgot to say that I tried this localization package before, called 'mozilla-locale-fr' from universe, with no success.

  11. Tim McCormack says:

    That's for the Mozilla suite, not Firefox. (I had a heck of a time getting that straightened out on my system.)

  12. cbonar says:

    Ok, my mistake, it was as you said : 'mozilla-firefox-locale-fr-fr'. I erroneously found the other one when I search back the exact name, but now I'm sure it was the 'mozilla-firefox-locale-fr-fr' I installed.

    Zorry ;)

  13. Bluewave Digital :: the blog » Ubuntu thus far says:

    [...] While on the topic of Firefox crashing, Flash. Flash video often crashes the browser. I’ve done every tweak under the sun to try to fix it, but it still occurs on various occasions. This is almost a show stopper as I frequent places like YouTube and the like. I guess java kills Firefox too. Who knows. All I know is that it is broken, and I don’t have the know how to fix it. [...]

  14. Stephan says:

    I am using the latest release of Ubuntu (6.10) and after installing the Flash player (from the Add/remove menu), the non free version, my Mozilla Firefox 2.0 always crashed on certain websites including Yahoo! Mail.

  15. Tim McCormack says:

    Check about:plugins -- are there multiple handlers for Flash, Shockwave, or Future Splash?

    In Synaptic (System -> Administration -> Synaptic Package Manager), search for packages with "flash" in their name. Which ones are installed?

  16. Wijoyo Utomo says:

    I can not reproduce this problem on my Dapper 6.06 and FF1.5.0.5. But I got another problem with FF streaming data from After logging into the FXGame account and java loads the applet, then the applet starts streaming in data for a minute or two, then the whole computer freezes up. Only mouse pointer the only thing that work.

    Any guide on fixing this? I've tried google'ing and found no result.

    [post edited by admin to fix URL formatting]

  17. Jim Caya says:

    This is a response the the flash plugin error that is so often found when running Firefox on Ubuntu.

    Far to common the situation is that the user is prompted to download the Macromedia flash plugin from a site which then causes the browser to crash anytime a site with flash plugins is visited.

    Then the user downloads all possible Flash plugins from the Add/Remove or Synaptic Package Manager which does not solve the problem.

    If this is you, help is here.

    The real problem is that your system is not setup to run the flash 7 plugin from Macromedia because of they way Macromedia wrote it (and the update will not be available for some time yet).

    Thankfully it is easy to work around this error by performing the steps below:

    1) Log in as "root" 2) Get to your file system (usually can be found by going to "Places" on the task bar) 2) Open the "etc" folder 3) Scroll down to the "X11" folder and open it 4) Find and open the "xorg.conf" file - NOT FOLDER 5) Scroll down until you see: but your "device" i.e. graphics card will be different

    Section "Screen" Identifier "Default Screen" Device "NVIDIA Corporation NV28 [GeForce4 Ti 4200 Go AGP 8x]" Monitor "Generic Monitor" DefaultDepth 16

    6) Change the default depth to 24:

    Section "Screen" Identifier "Default Screen" Device "NVIDIA Corporation NV28 [GeForce4 Ti 4200 Go AGP 8x]" Monitor "Generic Monitor" DefaultDepth 24


  18. Tim McCormack says:

    Well, Jim, this looks promising. I assume that the problem is that the flash plugin from Macromedia assumes it is working with 24-bit depth when this is not always the case, causing a crash?

    I checked my own xorg.conf, and it already had the 24-bit depth -- I had not modified this. Perhaps there are two problems here: bit depth assumptions with the Macromedia-supplied plugin, and multiple plugins attempting to handle Flash.

  19. Jim says:

    Thanks for that Jim, worked a treat.


  20. Rogerio says:

    Jim, if the user is running Ubuntu in a Virtual Server 2005 RC2, DefaultDepth 16 is mandatory. So, users in Virtual Server 2005 R2 can not use Flash plugin on Firefox.

  21. Jesus says:

    I seem to be having this same problem in Gutsy Gibbon, 7.10

    It doesn't immediately crash, but when pages have flash content, it becomes unstable. It is either slow and unresponsive or it just disappears in a magical way... Should I try one of these solutions? I probably have the mentioned library installed. Tried the second solution but the xorg file was not there...

  22. Kaeli says:

    Okay I would like to try this but I am not educated in the language of computers... what does it mean to log in as root and how do I do that?

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