Firefox Will Not Load On Our Linux Systems
Scenario: Firefox complains that there is another instances of firefox running.
First, make sure you really don't have another firefox running on some other machine on the net.
Then, in your home directory...
cd .mozilla/firefox/
cat profiles.ini
Look for your default profile name (which has a random string of characters.) Some people have multiple firefox profiles. Most people have only one.
Do an 'ls' to see that in that same directory is your profile directory.
Now...
cd profile
(You should be in a directory now that looks something like this:
.mozilla/firefox/jhjid5mz.default/lock
Your profile will have different characters, though.
ls -al
look for a file called lock
Normally, the lock file would have been automatically removed when firefox last exited, but sometimes, it does not get removed. So, we're going to have to remove it by hand.
Also, sometimes there is another leftover file called .parentlock (notice the dot before "parentlock") That file will also have to be removed by hand. (Note that dot files, like .parentlock, don't show up if you just type 'ls' which is why we're using ls -al The 'a' shows hidden files and the 'l' gives us a detailed listing.)
Therefore, remove the lock and .parentlock (if one exists) files from your profile.
rm lock
rm .parentlock
Restart firefox, and this time, firefox should load correctly.
You can also check out the following webpage that discusses the same issue: