Firefox will drop support for direct pre-installation of add-ons.
The developers of Firefox have decided to discontinue support for extensions that are installed through direct file copying to the extensions directory (/usr/lib/mozilla/extensions/, /usr/share/mozilla/extensions/, or ~/.mozilla/extensions/), which is processed by all instances of Firefox in the system (regardless of user). This method is usually applied for pre-installing extensions in distributions, substituting extensions during the installation of some application in the system, or for isolated delivery of an extension […]
