Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Denne tråden ble arkivert. Still et nytt spørsmål dersom du trenger hjelp.

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

  • 1 svar
  • 10 har dette problemet
  • 4 views
  • Siste svar av cor-el

switch
switch
more options

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.

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

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?