Unable to uninstall firefox add-ons

I tried uninstalling some addons in firefox installation in dr460nized edition.

  1. Normal mode and
  2. Safe mode
    but it is not allowed to uninstall.

Can you please mention why this is the case and whether I should uninstall the add-on manually which I do not intend to use?

Which add-ons are you trying to uninstall?
I think they can't be removed by Firefox because they were installed using pacman.
Try searching for Firefox extensions with pacman -Qs firefox or find the package names in the AUR.
You can then remove them with pacman -R.
I think I had to uninstall firefox-extension-localcdn by running sudo pacman -R firefox-extension-localcdn.