What error do you get?
You need to use the latest version of the firefox_getLatest.sh script, so enter this command in a terminal window:
md5sum /etc/sysconfig/tcedir/optional/firefox_getLatest.tcz
And check it returns this:
650f9d1c2ef095101b0a50c8941d0768 /etc/sysconfig/tcedir/optional/firefox_getLatest.tcz
If the first bit is different, run update-everything to update the whole system or
download the current version directly and move it to /etc/sysconfig/tcedir/optional/firefox_getLatest.tcz, replacing the existing file.