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Yesterday, Firefox downloaded a new version. After startup this morning I got the message "couldn't load XPCOM." Firefox will not load.

  • 4 replies
  • 2 have this problem
  • 2 views
  • Last reply by cor-el

numchuck
numchuck
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Yesterday Firefox downloaded an updated version. While my computer was installing it this morning I got the message: couldn't load XPCOM. I use Windows 7 home version.

Yesterday Firefox downloaded an updated version. While my computer was installing it this morning I got the message: couldn't load XPCOM. I use Windows 7 home version.

All Replies (4)

philipp
philipp
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hi, does it help if you download the full installer from https://www.mozilla.org/en-US/firefox/all/ and run the setup again?

numchuck
numchuck Question owner
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Will I lose my bookmarks when I reinstall Firefox or is there a way to save the bookmarks?

James
James
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  • Top 10 Contributor
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The settings are not in the Firefox program folder but in a separate place. You can backup your Profiles just in case though.

https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

cor-el
cor-el
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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.