Bundled HTTPS Everywhere breaks addon initialization

Update [sysrqb]: modified title. Https-e is broken, as well as preventing other addons from initializing.

Since the update to 11.0a9 some addons (specifically https://addons.mozilla.org/en-US/firefox/addon/custom-style-script/) are inactive and need disabling-reenabling on each start. The icon of the addon appears on the toolbar, but when clicked all the appearing options are inactive. The only way to make it work again is to go on the addons page, disable the addon and then re-enable. Each time the browser is started.