Can't set a breakpoint in Firefox Developer Edition (FDE) 's debugger pane

Question

I am running FDE 59.0b12 on Windows 10 64-bit; I am trying to follow the procedure/video shown at URL: https://developer.mozilla.org/en-US/docs/Tools/Debugger/How_to/Set_a_breakpoint in order to debug some JS code within a jQuery.ready() statement.

It seemed easy enough since I used to set breakpoints the same way with the former Firefox+FireBug combo. Except now I can't with FDE. None of the three methods explained works.

e.g. clicking on the line number just doesn't do anything. Same goes for right-clicking on the number, or the line. Am I doing anything wrong?

Answer 1

I've circumvented the issue by using Firefox 56. It is the last version before 57, therefore before the emergence of Firefox Dev Edition. I won't be using FDE until it gets fixed.