Adds on gone

Hello. I have moved to a new PC so was trying to install my usual Mozilla add-ons but I can’t find them anymore, whereas they are still available on my old pc. Why? And how can I get Google (Language: FR), Larousse,, and back?
Thanks in advance for making me understand/helping/pointing me to said missing add-on.

What version of Firefox are you running now and on the other PC? It sounds like you have been using some pre-57 version which supported old addons that doesn’t exists anymore (for a few years now).

There is multiple ways to move your Firefox to a new PC:

  1. you can copy your whole Firefox profile folder - this way all your settings, passwords and addons (and addons data) will be preserved on new PC. You can locate your profile folder from the “about:profiles” page.

  2. you can setup Firefox Sync. on your old PC and then just login to your Firefox account on the new PC - this will then synchronize your passwords, addons and other settings.
    I would recommend using Firefox Sync. even if you go with the profile copy way.

Thank you Juraj,

Synchronisation or Profile folder copy did not work.

I decided to find another solution with recent apps/tools.

Best wishes;