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Upgrading from Firefox 8 to Firefox 9 on Linux (Ubuntu Lucid) broke a feature I use often: Running multiple instances, then aiming command line Firefox at a specific running instance.

Any ideas on how to fix or work around this?

I run two Firefox instances with separate profiles:

firefox -no-remote -P personal
firefox -no-remote -P work

(The -no-remote is necessary for the second to start a new instance, and not just a new window in the first instance.)

I then use this to open a URL in one of the running instances:

firefox -P personal

This worked through Firefox 8, but in 9, I instead get the error message

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.

Same with these variations:

firefox -P personal -new-tab
firefox -P personal -new-window
firefox -P personal -remote "openURL(,new-tab)"

It looks like the initial -no-remote flag changed in Firefox 9 to also prevent connections from future command lines. If I start an instance without -no-remote, I can successfully open a tab in it from the command line, but I can't start a second instance that way, so that doesn't help much.

share|improve this question
this may be the same problem: – ryan Dec 30 '11 at 16:02
looks like this may have been caused by a "bug fix" in ff9 that made -no-remote also not listen for remote commands, in addition to not reusing a running instance. i'm talking with the mozilla people about it: – ryan Dec 30 '11 at 16:16
up vote 2 down vote accepted

jed davis posted a patch that fixes this by splitting a -new-instance flag out of -no-remote. hopefully it will land in an upcoming firefox release.

share|improve this answer
Seems to have landed. – Erika Sep 21 '13 at 10:38
hi @ryan, can you please write me some steps to follow to open my second profile called "Dev". Right now i am doing 1) open my default profile 2) launch dev profile with firefox.exe -P Dev -no-remote this works, but if i then do 3) `firefox.exe -P Dev -new-tab "about:blank" it wont open the new tab in it, it opens in the default :( – Noitidart Feb 8 '15 at 12:30
Oh im using Windows – Noitidart Feb 9 '15 at 2:25
@Noitidart good question! i'm not sure how to target different windows via the command line, especially on windows. sorry. – ryan Feb 9 '15 at 16:28
Thanks @ryan for the reply, I'll dig around in the buzilla topics linked, thanks for your effort on this. :) – Noitidart Feb 9 '15 at 17:31

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