*** Please submit non packaging issue (e.g. feature requests) bugs to
the Debian BTS and the upstream bugzilla
(https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox) and put a
reference to the bugzilla bug in the Debian bug report to ease bug
triage for the maintainers. You may need to reproduce this with
upstream's Firefox for upstream to take you seriously. Thank you. ***

Firefox ESR extensions being a big source of problems, please either try
to reproduce your bug with a clean user or with your current user in
safe mode, with the "firefox-esr -safe-mode" command line before filing
any bugs.  If your bug disappears with a clean user or in safe mode,
you might want to find which extension is responsible for it and file
a bug to the appropriate package, bug tracking system, or author.

If your previous Firefox ESR installation pre-dates 3.0, you might have
had problems since upgrading from one release to another can lack clean
support for some features.  Please try moving your ~/.mozilla/firefox
directory out of the way to see if it helps with your issue.

Firefox ESR requires the loopback interface (lo) to be up and unfiltered
to accept keyboard input and function correctly. Please make sure this
is the case before filing any bugs.

If you get crashes and none of the above hints helped, please also
try to run "MOZILLA_DISABLE_PLUGINS=1 firefox-esr".

If Firefox ESR still crashes, please submit the crash to Mozilla, then
visit `about:crashes` and paste the url to the corresponding submitted
crash report in your bug report.

Alternatively, please install the firefox-esr-dbgsym package and run
Firefox ESR under gdb with:

    gdb --args firefox-esr [command-line-arguments]

At the gdb prompt, type the following commands:

set pagination off 
run 
bt full 

And attach the resulting backtrace to your bug report.

If you see XML parsing errors, please make sure you kill all running
Firefox ESRs and reload before filing any bugs.