[Legacy Addon] loadFrameScript broken in Firefox 56?

Add-ons Development
#1

Here’s an example extension that uses loadFrameScript and a listener. This kind of code worked in Firefox 55 and earlier (I’m using it in an actual addon with multi-year history), but fails in Firefox 56.

Or to be more specific, it does what’s expected when the tab is showing some chrome URL (like the Addons page) but does nothing in tabs that show web pages.

Expected behavior:

  1. Press Ctrl-Alt-D.
  2. See {num: 42} in the Browser Console.

The xpi is here: https://ufile.io/vagyh

What am I doing wrong?

#2

Looks work for me, Alt+Shift+D in Fx55 x86 & Fx56b1 x64, on about:addons & http://start.firefoxchina.cn/.

#3

Thanks for testing, but it really doesn’t work here on web pages, with a new profile and everything, not even even on http://start.firefoxchina.cn/.

Firefox 56.0b1 (64-bit), on Ubuntu 16.10.