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

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  • 1 has this problem
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  • Last reply by FredMcD

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Hello Team, Firefox is already running but not responding. The old firefox process must be closed to open a new window. I'm running a windows 10 laptop. I tried to resolve this issue 1) through task manager, but the issue didn't resolve mentioned in the browser 2) Remove the profile lock file, but it didn't show any folders/files.

However I'm able to install and use other browsers like edge, chrome and opera. Can someone help me to resolve this issue and use firefox browser?

Attached screenshots

Modified by harishedamad

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FredMcD said

Have you tried rebooting the computer? https://support.mozilla.org/en-US/kb/firefox-already-running-not-responding https://www.basezap.com/cant-open-firefox-because-a-copy-of-firefox-is-already-open-mac/ https://apple.stackexchange.com/questions/196771/cant-open-firefox-because-a-copy-of-firefox-is-already-open http://kb.mozillazine.org/Firefox.exe_always_open

Hi FredMCD Thanks for sharing these resources. I did try them especially the first one, but didn't do a system restart. I don't know what's the issue, but after installation of a new antivirus software the problem was solved, and the previous free antivirus software and the new full-version software didn't show any sign of virus/trojan horse infection. Now I'm posting this message from firefox.

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FredMcD said

Have you tried rebooting the computer? https://support.mozilla.org/en-US/kb/firefox-already-running-not-responding https://www.basezap.com/cant-open-firefox-because-a-copy-of-firefox-is-already-open-mac/ https://apple.stackexchange.com/questions/196771/cant-open-firefox-because-a-copy-of-firefox-is-already-open http://kb.mozillazine.org/Firefox.exe_always_open

Hi FredMCD Thanks for sharing these resources. I did try them especially the first one, but didn't do a system restart. I don't know what's the issue, but after installation of a new antivirus software the problem was solved, and the previous free antivirus software and the new full-version software didn't show any sign of virus/trojan horse infection. Now I'm posting this message from firefox.

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That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems.

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Hi FredMCD,

Thanks for your support, this problem is solved

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Please flag your https://support.mozilla.org/en-US/questions/1345860#answer-1432935 post as Solved Problem as this can help others with similar problems. Go to that post and click the 'Solved' button to its right.

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Can you please share the screenshot where I need to flag that this problem is solved, because, I get your update whenver you post and in that I get the button "Mark it as solved".

I've already did press as Mark it as solved, I didn't know why it's not solved, even it's showing as "Chosen solution button with tickmark" on my question, I have attached the screenshot for same.

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Look at your first picture. The post is flagged as 'solved.'

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