when I type firefox, I get this message then mozilla quality feedback windows pops up

this is what it says in the terminal, and I don't understand any of it.

(process:30898): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
Fontconfig error: Cannot load default config file

(firefox-bin:30898): Gdk-WARNING **: gdkdrawable-x11.c:764 drawable is not a pixmap or window
./run-mozilla.sh: line 131: 30898 Segmentation fault "$prog" ${1+"$@"}

How can I fix this ?
Thank You

Is this a Slackware package that you installed, or did you download Firefox from mozilla.com?

Assuming you use Slackware, as it's noted in your profile...

I download this from firefox. It was running ok until, I play with pango, cairo, atk. I upgdrade with these things and then firefox get sick after that.
Thank You

Well, you've answered your own question. Firefox is rather particular about those libraries.

You can restore the original versions of those libraries to where they were in the system, or you could try copying the original versions into your firefox installation directory. You will see there are already many libraries there, and firefox should look in there before the system directories when searching for libraries.

Did you also possibly upgrade libgtk-x11-2.0.so.0 and libgdk-x11-2.0.so.0? Looking in my firefox-1.5 directory, I see I copies those libraries there to fix a similar problem.

Cheers.

Jim

Yes I did, I upgrade all those libraries, and now linux won't even go online

uninstall firefox and then install the new version

I have much the same problem. I've reinstalled gtk2, gtk, pango, and multiple other dependencies to fix this. Im now using the alpha build of 2.0, but that fixes nothing. I'm not exactly sure what it causing it. Googling this problem results in a bunch of results, but none of their solutions have worked for me.