An installation guide for non-developers would have helped. I did not understand why installing another client was needed for the extention to work. Maybe a youtube video with sound could explain step by step what each part does. Since all the changes with Firefox seem to be motivated with security aspects, It seems strange that the first "new" compatible extention demands that you install a n "extra client " out of an obscure package called "windows", found somewhere in the internet. And that client program does not even have a name, nor an install path, it just installs somewhere into your system.

Besides all that, the downloader still simply failed to download, even with the extention installing allright (It did check green). Then the first downloadable file, a mp3, produced just a "error spawn" message with a cryptographic text. That was 20 minutes in and I just uninstalled it alltogether. Why was downthemall or flashgot able to do what you'd expect even back in 2006?

I do not undersstand why people put so much effort into creating these AddOns and nearly zero into conveing their product to the user.
Really astonishingly bad user experience in 2017.

Was easy and worked fine. Now complex crap

Not work for authenticated sites... not send http auth and cookies to fdm....

IT DOES NOT WORK !!!!!!!!

Completely not works for me, even after install the component in "windows.zip".
Check connection always told me no native client . Windows 7 x64 + FF57

Somehow, I found out that FDM 5.1.33 has been released, as it claims working for FF57.
After FDM 5.1.33 installed & enable extension in its setting again, everything works as old day.
https://image.prntscr.com/image/VM7RUK25TN6VTN10CmCImQ.png

FDM 5.1.33 official release
https://www.freedownloadmanager.org/download.htm
http://www.freedownloadmanager.org/board/viewtopic.php?f=1&t=17363&p=41704
- Added Firefox 57+ support.

I installed the app, installed the "native client" and clicking on downloads did not pass them to FDM, they just downloaded as normal. This addon is not developed by the official FDM team and the whole thing seems a bit dodgy to me.

This new version works nothing like the old version. It's like it is not even the same program.

if it doesn't increase download speed then this is just a redundancy.