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firefox is unable to determine if there is an update available error message often in windows 10

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  • Last reply by philipp

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I get the message box saying "Firefox is unable to determine if there is an update available" at least once per day. Running Windows10 Pro yet when I check "About Firefox" in HELP tab it shows that it is Version 42.0 and shows "Firefox is up to date" after checking that way.

I get the message box saying "Firefox is unable to determine if there is an update available" at least once per day. Running Windows10 Pro yet when I check "About Firefox" in HELP tab it shows that it is Version 42.0 and shows "Firefox is up to date" after checking that way.

Chosen solution

hi stephenichols, thanks for providing you troubleshooting information. it appears that you have a user.js file present in your profile which is often a sign of malware on a system (unless you've created that file manually).

please go to the firefox menu ≡ > help ? > troubleshooting information > profile folder - "show folder", then a new window will open up. in this window look out for a file named user.js - delete or rename this file and restart firefox.

afterwards, please run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

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Chosen Solution

hi stephenichols, thanks for providing you troubleshooting information. it appears that you have a user.js file present in your profile which is often a sign of malware on a system (unless you've created that file manually).

please go to the firefox menu ≡ > help ? > troubleshooting information > profile folder - "show folder", then a new window will open up. in this window look out for a file named user.js - delete or rename this file and restart firefox.

afterwards, please run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware