I checked Firefox plugins for up-to-date-ness. Java was out-of-date. When I tried to upgrade with the non-rpm 32-bit version Firefox showed a blank screen and halted. I had to kill it. ps revealed that it was trying to:

which was 176-byte error file; apparently jre-7u51-linux-i586.tar.gz isn't.

When I started Firefox again it did the same thing. When I deleted Firefox's cache with an rm -rf when Firefox wasn't running it still did the same. Resetting cleared the error. I downloaded the rpm then converted it to a tgz to install java.

Why does this make Firefox halt?

what operating system ?
assuming Slack ? if so what version ?

also FF can update by clicking on "help" and from there "about firefox"
on that pop up there is a button " check for updates "

as to JAVA
what was being used Openjdk or Oracles java

in current( as of 18) firefox versions ( for the prebuilt )
-- 64 bit --
https://ftp.mozilla.org/pub/mozilla....x-27.0.tar.bz2

the plugins folder was moved from the
installfolder/plugins
to
installfolder/browser/plugins

linux

I check for updates daily. I haven't done anything version-based in years.

I use Slackware packages for Firefox. When I upgrade I sometimes check plugins for update in 'about: plugins'

Oracle's. I don't know about OpenJDK: what's a good reason to switch?