solution Rated 5 out of 5 stars
Did you delete the installed one? it's necessary!I
For FF 20, do the same, delete and reinstall!
And if, like me, you don't like the new download manager, open "about:config" and put "TRUE" to "browser.download.useToolkitUI"
Rated 5 out of 5 stars
Just awesome!This review is for a previous version of the add-on (10.3).