<Add-on> could not be installed because Firefox cannot modify the necessary file.
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.
All Replies (1)
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?
- 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?