I killed Firefox on my MacBook Pro laptop running OS X Yosemite (10.10.5) by clicking on the Apple icon at the upper, left-hand corner of the screen then selecting Force Quit and then selecting Firefox and clicking on the Force Click button.
But when I tried to reopen Firefox, I saw the message 'You can't open the application "Firefox.app" because it is not responding.'
I clicked on OK and used Force Quit Applications again. I saw
Firefox in the list and again forced it to quit. I then clicked on the Firefox
icon in the
Dock at the bottom of the screen again, but Firefox didn't appear to open.
I double-clicked on it again, but it still didn't appear to open, though it
appeared in the Force Quit Applications list again with "not responding"
appearing next to its entry in the list of open apps. I tried clicking on the
Firefox icon in the Dock a third time and this time saw the 'You can't open
the application "Firefox.app" because it is not responding' message again,
though reopening Force Quit Applications again did not show "not
responding" next to the Firefox entry in its list. Nor was any other
application listed as being unresponsive. I tried the Force Quit
step again. Firefox remained in the list until I closed and reopened
Force Quit Applications. Though Firefox wasn't in the Force Quit
Applications list, I did see a process associated with Firefox
when I used the ps command to view processes running on the system.
$ ps -ef | grep -i Firefox | grep -v grep 723184451 6861 1 0 8:46AM ?? 0:00.03 /Applications/Firefox.app/Conte nts/MacOS/plugin-container.app/Contents/MacOS/plugin-container /Library/Internet Plu g-Ins/JavaAppletPlugin.plugin -greomni /Applications/Firefox.app/Contents/Resources/ omni.ja -appomni /Applications/Firefox.app/Contents/Resources/browser/omni.ja -appdi r /Applications/Firefox.app/Contents/Resources/browser 1635 gecko-crash-server-pipe. 1635 org.mozilla.machname.776527788 plugin $
I killed that process with the kill command.
$ kill -HUP 6861 $
But when I again double-clicked on the Firefox entry in the Dock, the program didn't appear to open, though I could see it in the Force Quit Applications list and I could see a process running using the ps command. I killed that process using the kill command.
$ ps -ef | grep -i Firefox | grep -v grep 723184451 7345 1 0 11:07AM ?? 0:00.06 /Applications/Firefox.app/Contents/MacOS/firefox $ kill -HUP 7345 $ ps -ef | grep -i Firefox | grep -v grep $
But I still couldn't access Firefox after again trying to start it from the
Dock. I then tried opening the Activity
Monitor app found in Applications/Utilities, but I couldn't
see that open application either. As with Firefox, it didn't appear when I
cycled through open applications with command-tab (you can move from
one open application to another by hitting the commandt-tab keys
repeatedly). Though I did see the Firefox icon in the Dock, I didn't see
one for Activity Monitor. But clicking on the Firefox icon in
the Dock did not open it so I could use the program. Nor did clicking
on it and choosing Open.
I tried the killall command, but that didn't help; Firefox still didn't appear afterwards when I tried opening it.
$ killall Firefox No matching processes belonging to you were found $ killall firefox $
The results were the same when I tried opening Firefox from a Terminal window with the open command.
$ open -a /Applications/Firefox FSPathMakeRef(/Applications/Firefox) failed with error -43. $ cd /Applications $ open -a Firefox $
I checked the system's CPU utilization, but it was very low and Firefox was getting zero CPU cycles.
$ top Processes: 230 total, 2 running, 9 stuck, 219 sleeping, 929 threads 11:54:14 Load Avg: 1.73, 1.57, 1.56 CPU usage: 0.12% user, 0.36% sys, 99.51% idle SharedLibs: 12M resident, 18M data, 0B linkedit. MemRegions: 29950 total, 2690M resident, 121M private, 654M shared. PhysMem: 8902M used (1607M wired), 7477M unused. VM: 542G vsize, 1065M framework vsize, 0(0) swapins, 320(0) swapouts. Networks: packets: 757278/660M in, 807747/207M out. Disks: 1177060/19G read, 576078/31G written. PID COMMAND %CPU TIME #TH #WQ #PORT MEM PURG CMPRS PGRP PPID 7448 ocspd 0.0 00:00.00 1 0 18 1232K 0B 0B 7448 1 7447 CVMCompiler 0.0 00:00.06 2 1 31 12M 8192B 0B 7447 1 7445 automountd 0.0 00:00.01 7 0 31 1468K 0B 0B 7445 1 7444 top 1.9 00:01.55 1/1 0 22 2012K 0B 0B 7444 479 7441 warmd_agent 0.0 00:00.02 2 1 41 1872K 0B 0B 7441 1 7439 mdworker 0.0 00:00.04 4 0 49 6764K 0B 0B 7439 1 7436 System Prefe 0.0 00:00.01 2 0 49 1496K 0B 0B 7436 1 7420 firefox 0.0 00:00.05 22 0 84 13M 0B 0B 7420 1 7409 Finder 0.0 00:00.06 2 0 83 5260K 0B 0B 7409 1 7387 mdworker 0.0 00:00.04 3 0 50 1712K 0B 0B 7387 1 7385 CoreServices 0.0 00:00.01 2 0 49 1284K 0B 0B 7385 1 7368 mdworker 0.0 00:00.38 4 0 49 12M 0B 0B 7368 1 7364 QuickLookSat 0.0 00:00.21 2 0 43 2344K 0B 0B 7364 1 7279 quicklookd 0.0 00:00.17 4 0 98 5216K 0B 0B 7279 1 7231 netbiosd 0.0 00:00.94 5 4 42 1616K 0B 0B 7231 1 7137 eapolclient 0.0 00:00.12 3 0 49 3264K 0B 0B 7137 55 6893 GoogleSoftwa 0.0 00:00.02 2 0 47 1564K 0B 0B 6893 1
I hit function key F3, but the window wasn't on another desktop. I tried logging out, but couldn't log out - eventually a window appear informing me that I couldn't log out because system preferences wasn't responding - I had tried opening it during the troubleshooting process. I used Force Quit Applications to kill it. I then tried logging off again, but saw a similar message, though this time referencing Firefox. So I used Force Quit Applications to kill it. I then tried logging off again, but saw a similar message again, though this time there was no reference to a specific app.
Your Mac hasn't logged out because an app failed to
quit. To try to continue logging out, click Try Again.
To quit an unresponsive app, select Force Quit from the Apple
Menu (or press Command-Option-Esc).
Clickng on Try Again simply resulted in the same message appearing. I
used the command-option-escape keys to bring up the Force
Quit window and killed the Terminal window leaving only
the Finder showing in that window. I then tried logging out by using
the command-shift-q keys, but I still couldn't log out.
I still saw the message "Your Mac hasn't logged out because an app failed
to quit." I had brought up the Force Quit Applications window
previously and selected Finder, which allowed me to relaunch
Finder, but that hadn't help with the problem, so I finally
just powered the system off and on using the power button. After the
system rebooted the problem was no longer there. I could open Firefox
and other applications and the windows were visible whereas before,
if there were windows associated with the applications I was opening
they seemed to be invisible ones.