Lỗi Firefox trong Ubuntu – Opening firefox, says is already running, close existing process

So, today I was playing around with some different emerald themes, and to apply it I logged out and logged back in. I am very religious about closing my applications before logging out or shutting down a system. So I found it interesting that I still received a firefox error upon returning to my desktop. Error: “Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system”.

Well, is that so? I can only assume that maybe while trying to apply the new theme to the application it hung, or perhaps my user processes were not completely closed when I logged out. In any case, below is a screen shot of the error:

Whole Desktop

Firefox Error

Well, for those who would rather not restart their system, there is an easy way to resolve this.


Open a terminal, and run the following command:

$ps aux | grep firefox

PS Command

What this does, is it asks the system to list the running process. Using the “grep” command is just applying a filter for “firefox”. IF you notice the second to last process is my firefox process. the PID or “process ID” is “5719″. The first column will list what user is running the process, and the second column will show the process ID. Now we can just kill the process by running another command in the temrinal of

$sudo kill -9 5719

What this is doing is telling the system to just kill the process, the equivalent of “end task” in Windows. You should now be able to just relaunch Firefox without any errors.

To see all the processes running just run a:

$ps aux

from your command line and you can see all the processes running and the corresponding information for each.


By dbglory Posted in Linux

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