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XPCOM and New Download of FIrefox

  • 5 cavab
  • 2 have this problem
  • 3 views
  • Last reply by riniyy01

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Couldn't open Firefox XPCOM error.

Downloaded Firefox again and I now have Firefox in OS/Program Files/Mozilla Firefox (which doesn't work - XPCOM error) and a second version in OS/Program Files (x86) which works but has lost all my bookmarks and passwords.

How can I fix this please.

Couldn't open Firefox XPCOM error. Downloaded Firefox again and I now have Firefox in OS/Program Files/Mozilla Firefox (which doesn't work - XPCOM error) and a second version in OS/Program Files (x86) which works but has lost all my bookmarks and passwords. How can I fix this please.

All Replies (5)

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You can download the 64-bit version of the current 102 release and remove both 32-bit and 64-bit versions you currently have installed.

  • (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
  • (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

Then reinstall the 64-bit Firefox 102.0 version you previously downloaded.

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Thank you for your answer cor-el. Just confirming that I remove (delete) the existing 32-bit and 64-bit versions before reinstalling the 64-bit Firefox 102.0 version?

When activated, will the new downloaded version have my existing bookmarks and stored passwords?

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You can possibly keep the 64-bit version and reinstall a newly downloaded copy like I posted above. That increase the possibility that Firefox reuses your old profile. If Firefox insists in creating a new profile then remove compatibility.ini in the profile.

See also:

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So appreciate your help cor-el - it all worked perfectly and I have all my bookmarks, etc. Thank you.

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This issue would normally be fixed with a clean reinstall that involved deleting the Firefox program folder.

(64-bit Firefox) "C:\Program Files\Mozilla Firefox\" (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

An error message about XPCOM missing or about platform version usually happens because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox program folder. This can happen in case security software was keeping a handle of some of the files in the Firefox program folder preventing Firefox from replacing all the files. You can do a clean reinstall to ensure that all files are replaced. You may have to disable security software temporarily in case the problem persists.