If I recall signatures.required is disabled in main firefox for security reasons. You need Firefox Nightly or Firefox Dev edition to use it. Anyway I changed to chrome for my plugin.
Edit: found some info about it
> Setting xpinstall.signatures.required to false will not work on the Beta or Release versions of Firefox on Mac or Windows. Doing so has no effect. On Linux, depending on your distribution, the setting may be respected and does work on some distributions of the release version of Firefox.
Edit: found some info about it
> Setting xpinstall.signatures.required to false will not work on the Beta or Release versions of Firefox on Mac or Windows. Doing so has no effect. On Linux, depending on your distribution, the setting may be respected and does work on some distributions of the release version of Firefox.
https://superuser.com/questions/1432789/all-of-my-firefox-ad...