firefox freezes when trying to play flash video

Which Firefox, which Ubuntu, which flashplayer?

firefox --version
lsb_release -d
locate libflashplayer.so

To avoid conflicts and usage of older versions you may check how many and which flash apps are installed, via Synaptic, keyword flash. In case remove all and install your favourite only.

firefox --version --> "Mozilla Firefox 3.0.12, Copyright (c) 1998 - 2009 mozilla.org"
lsb_release -d --> "Description: Ubuntu 8.10"
locate libflashplayer.so --> "/usr/lib/flashplugin-nonfree/libflashplayer.so"

I dont think I have other flashplayers installed at all, nothing shows up in synaptic anyway.

Thanks for the information.
32 or 64bit Ubuntu?
You may give it a try to remove flashplugin-nonfree completely via Synaptic (anyway you can reinstall it) and try directly from adobe.
I never had any issue with it, e.g. fullscreen, compiz, pulseaudio, websites.
http://labs.adobe.com/technologies/flashplayer10/

I use 32-bit ubuntu.

I tried to do as you suggested. Removed the flashplugin-nonfree package and installed the flashplayer from adobe. The same problem is still there however.

Sorry that it failed.
Firefox was closed and you did restart it after installation?

You may try adobe-flashplugin like Lanza did here.
https://answers.launchpad.net/ubuntu/+source/firefox-3.0/+question/78067

Again make sure only one flash app at a time.

If nothing helps and you're using compiz, try to deactivate it (visual effects=none) in
system preferences -> appearance

In case to get some messages start firefox in a terminal.
Or check .xsession-errors in your /home/username directory.
Use the Help button for 'Report a problem' to generate and upload an Apport crash file in order to report a bug.
https://help.ubuntu.com/community/ReportingBugs
https://wiki.ubuntu.com/DebuggingProcedures

Btw I forgot to mention the videos on the sites mentioned above was working with no problems at some point in the past. Firefox only recently started freezing up like this. I dont remember when exactly it started but I think it must have been about a month or two ago. However in that period of time I am reasonably sure I have not installed anything new that should have an effect on the problem (actually I am pretty sure I have installed nothing new at all).
So expect the problem must have been introduced by one of the updates that ubuntu tells you to install now then.

Yes I did restart after I installed the new plugin. In fact I restarted after I removed the first plugin to check that no flash video would play (as expected).
After installing the new plugin I restarted once more and the problem was back to the exact same as with the first plugin. That is most flash videos played as they should, but the videos on certain sites (those mentioned above) caused firefox to freeze.

I tried copying Lanza's solution just now, but the command
sudo apt-get install adobe-flashplugin
Only gave an error message saying something along the lines of "the adobe-flashplugin package has no installation candidate" (translated from danish).

After that I reinstalled the plugin from adobes site and tried running firefox from a terminal. That however gave no messages in the terminal at all, and there is no messages in the .xsession-errors file either.

So the problem still seems unsolved. Thank you very much for your suggestions though :).

Hi

Can you use Synaptic Package Manager (sorry i don't know the command-line version you've been using very well) to search for all the flash players you have installed on your system? Sometimes if you have 2 or more they can clash with each other. I would uninstall them all and then reinstall the 1 main one again

System - Administration - Synaptic

the search button is the best search tool imo.
Good luck and regards from
Tom :)

Not to be rude, but that is pretty much the same suggestion as Sam gave. As you can see I tried that and it failed.

> a month or two ago

History search in Synaptic? Not really an option after such a long time.

Ok, other options.
Worse case scenario, backup your bookmarks, note addons and rename /.mozilla
e.g.
.mozilla.broken

Restart firefox and test the websites with your favourite flash app.

You may also check about:plugins (insert in url bar) if plugin is correct implemented.
In addition you may add back addons successive.

There shouldn't be different versions of flash apps in
/usr/lib/flashplugin-nonfree/
~/.mozilla/plugins

Maybe it helps to remove folders with #
in
.macromedia/Flash_Player/macromedia.com/support/flashplayer/sys
and
.macromedia/Flash_Player/#SharedObjects

To review settings
http://www.macromedia.com/support/documentation/de/flashplayer/help/settings_manager03.html

If you're using radeon driver you may add to device section of xorg.conf
Section "Device"
 Identifier "Configured Video Device"
 Option "AccelMethod" "EXA"
EndSection

Of course backup system files before edit
cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup

Just for checking if this is a FireFox issue or some more general issue you can search and then play the particular video on youtube by Totem Movie Player, the default player of Gnome desktop. To do this click on Playlist button and choose YouTube.

Or use there "Open Location..." with the exact address of the video.