Rated 5 out of 5 stars

THANK YOU very, very much, LeeToo.

What he said is true:
"It's very simple to get work this extension for firefox 38.x!" -- 40.0.2 now.


Find inside your system partition the installed add-on "extensionlistdumper@sogame.cat.xpi"

Now copy it to (e.g.) your desktop and open it with 7-zip program. Find the item "ELDumperOutput.js"
That's the path: \extensionlistdumper@sogame.cat.xpi\chrome\chromeFiles\content\ELDumperOutput.js

Right click over it and hit Edit

Find the line:

var XPIProvider = Components.utils.import("resource://gre/modules/XPIProvider.jsm")

and chang it to:

var XPIProvider = Components.utils.import("resource://gre/modules/addons/XPIProvider.jsm")

Save the modification and install the add-on. Just choose to open it with FFox -- or drag and drop it to the browser.
Then restart.

That's it, the list now is there for copying or saving.