Comment 1 for bug 203742

Thanks for reporting this bug to help make firefox and Ubuntu better!

Here are a few things to try to help diagnose this issue.

1) Are you using any plugins or extensions? If so try creating a new profile and see if the bug persists.

To do this start firefox with: firefox -ProfileManager
Be careful not to delete your profile. It can erase the whole directory that the profile is saved in!
Make a new profile, see if the bug remains.

2) Start Firefox fromteh terminal

Enter: firefox in a terminal
Please upload the output of running this command. Also provide any output at the time of the crash, if you can see it.

3) Install debugging packages run:

# sudo apt-get install firefox-dbg \
     libgtk2.0-0-dbg \
     libnss3-0d-dbg \
     libnspr4-0d-dbg \
     libpango1.0-0-dbg \
     libc6-dbg

4) After closing all instances of Firefox, start Firefox from the terminal with the following command:

firefox -g 2>&1 | tee ~/Desktop/gdb-firefox.log
... # some output
(gdb) run
... # run and reproduce crash
(gdb) bt full
... # full backtrace output
(gdb) thread apply all backtrace full
... # all threads full backtrace output
(gdb) quit

Now ~/Desktop/gdb-firefox.log will contain infos we need to initially process your crash bug. So, please attach that file to your bug report.

5) Copy and paste in a xterm the following command:

TMPDIR=$(mktemp -d)
apport-unpack /var/crash/_usr_lib_firefox_firefox-bin.1000.crash $TMPDIR
gdb -nx /usr/lib/firefox/firefox-bin -core $TMPDIR/CoreDump -ex 'backtrace full' -ex 'thread apply all backtrace full' -ex 'quit' 2>&1 | tee gdb.log
rm -fr $TMPDIR

That command will run gdb against the coredump file included in the crash report that was generated when firefox crashed.

Upload the resulting gdb.log to launchpad.

One good thing to do is looking at the gdb output and search for missing dbg libraries or other warnings, install them and run again gdb.

With this additional information, the devs should be able to help with this bug.