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<Add-on> could not be installed because Firefox cannot modify the necessary file.

Posted

I see that for the issue:

<Add-on> could not be installed because Firefox cannot modify the necessary file.

The usual fixes include: - ensuring that xpinstall.enabled is set to true - ensuring that extensions.alwaysUnpack is set to true

What might be the non-usual fixes as I have set both to true and I still get the message above.

I have tried installing the <add-on> after I have set the values to true, then again after restarting my browser, then again after restarting my computer and finally tried creating a new profile and repeated each of the steps after setting the 2 preferences to true.

I see that for the issue: <Add-on> could not be installed because Firefox cannot modify the necessary file. The usual fixes include: - ensuring that xpinstall.enabled is set to true - ensuring that extensions.alwaysUnpack is set to true What might be the non-usual fixes as I have set both to true and I still get the message above. I have tried installing the <add-on> after I have set the values to true, then again after restarting my browser, then again after restarting my computer and finally tried creating a new profile and repeated each of the steps after setting the 2 preferences to true.

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Application

  • User Agent: Mozilla/5.0 (Windows NT 5.1; rv:10.0.3) Gecko/20100101 Firefox/10.0.3

More Information

Windows XP and Firefox 10 (I cannot upgrade my browser to a new version)

cor-el
  • Top 10 Contributor
  • Moderator
12528 solutions 115514 answers

Can you at least update to the latest Firefox 10.0.10 ESR version?

Firefox 10.0.x ESR:


So a new profile with no other extensions didn't work as well?

Which extension is causing this problem or can't you install any extensions at all?

Can you at least update to the latest Firefox 10.0.10 ESR version? Firefox 10.0.x ESR: *http://www.mozilla.org/en-US/firefox/organizations/all.html ---- So a new profile with no other extensions didn't work as well? *https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles *http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues Which extension is causing this problem or can't you install any extensions at all? *http://kb.mozillazine.org/Unable_to_install_themes_or_extensions *https://support.mozilla.org/kb/Unable+to+install+add-ons