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I try to open Firefox. Get error message saying Firefox is already running and needs to close - another error message say Firefox can't open

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  • Last reply by FredMcD

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Turned on laptop (rebooted) after being away from it for a few hours. Went to open my home page. Error message popped up saying Firefox is already running and must be closed. I closed it and another error message popped up saying Firefox can't open - incomplete or missing files.

I went into Processes to close Firefox. Selected 'end process' but nothing happened.

Tried to use Internet Explorer but it just gets hung up. Cannot access anything.

And, because I can't open Firefox, I can't go a refresh.

Everything was working just fine a few hours ago.

Any thoughts?

Turned on laptop (rebooted) after being away from it for a few hours. Went to open my home page. Error message popped up saying Firefox is already running and must be closed. I closed it and another error message popped up saying Firefox can't open - incomplete or missing files. I went into Processes to close Firefox. Selected 'end process' but nothing happened. Tried to use Internet Explorer but it just gets hung up. Cannot access anything. And, because I can't open Firefox, I can't go a refresh. Everything was working just fine a few hours ago. Any thoughts?

All Replies (2)

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Firefox hangs or is not responding - How to fix

Open the Task Manager and quit the process. If this continues to happen I would recommend starting the PC in Safe Mode with networking.

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What is the computer system and Firefox on the bad computer?


Separate Issue; Your System Details on this computer shows;

Multiple versions of your Adobe programs.

Having more than one version of a program may cause issues.

Go to adobe.com and download the full installers after removing all of the old programs.


Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options)
key, and then starting Firefox. Is the problem still there?


This is not a cure but will make it easier if Firefox locks up in Windows. https://support.mozilla.org/questions/997866 {web link}