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Firefox keeps saying previous instance of Firefox not closed when it is before opening new instance.

  • 7 replies
  • 1 has this problem
  • 26 views
  • Last reply by dwpruitt

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If I open a website with Firefox then close browser and go to open another site on my desktop, Firefox says " Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window". If I hit the close tab, the new site opens. I cannot find any other instances of Firefox running when it says this. Other browsers, Chrome etc. do not exhibit this behaviour. Any ideas ?

If I open a website with Firefox then close browser and go to open another site on my desktop, Firefox says " Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window". If I hit the close tab, the new site opens. I cannot find any other instances of Firefox running when it says this. Other browsers, Chrome etc. do not exhibit this behaviour. Any ideas ?

Modified by ribbonmicsrus

All Replies (7)

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Is this a common occurrence for you? Restarting your computer should fix the issue for you.

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No, its not that, I am reasonably experienced with computers and have been through all the usual pros and cons of browser setup.

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Information shared about your system shows that you have a User.js file in your Firefox setup. This file can often cause issues.

Try going to your Firefox profile folder and rename the user.js file to user.js.old. Then restart your computer and see if the issue goes away.

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Interesting, after following recommendation, no difference. But have noticed its only one particular site that appears to bring this problem up. It is https://nefleaglecam.org/

If I open it, then close Firefox and open it again a box comes up with " Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window"

Trying this in Chrome does not invoke this problem. Not that its areal problem!, more curious as to why. Regards Andy

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ribbonmicsrus said

https://nefleaglecam.org/

If I open it, then close Firefox and open it again a box comes up with " Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window"

Why are you opening and closing and opening FF? I'm taking this means you're doing this in rather quick succession or do you have many minutes/hours passed between sessions?

Right after I Exit FF, I see that all the browser windows are gone, but in Task Manager, there are still FF Processes busy closing. It depends on how many browser windows and Tabs are going.

Example: My 20 FF windows, with one having over 1,400 Tabs, can take nearly 1 minute for all of FireFox.exe's to close.

I'm guessing if you close and start-up too quickly, you get that error:

"Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window."


~Pj

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Thanks PJ, as I said its really only curiosity that only this site does it, I can come back 1/2 hour later and same situation. It only does it on Firefox so guess its something in that site setup that Firefox does not like. Not being a web designer, cant answer that one.! Case closed now, many thanks to all.

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I am having same issue, did you solve it? also keeps asking to set as default, when it is set as default