I had the same problem. Check out my solution; Installing NodeJS = What is this about?

I sent a message to FreeDownloadManager, but they have not responded http://www.freedownloadmanager.org/support-center/tickets.php?id=7533

I'm trying to use the mozilla addon to download youtube videos. when I click on the Video Download Helper icon I get an error message saying I have to install the companion app.I download it, and snap installs it. Then when I try to download the video I again get the error message that I have to install the app. If I left click on the VDH icon it says that the app is not installed.

I'm trying to use the mozilla addon

Hi, unfortunately there is a very slim chance you will run across a Mozilla Firefox Extension. The Extension you are trying to install has nothing to do with Mozilla or Firefox. If the Extension meets the criteria a web page is granted to the Developer of the Extension to distribute the Developers Extension.

Now this is the URL : https://addons.mozilla.org/en-CA/firefox/addon/video-downloadhelper/ Please seek Help from them : Home Page : www.downloadhelper.net/ Support : www.downloadhelper.net/support.php

I would take a great big look at the Permissions you allowed for this program to run.

As for the program not running on Linux.

Myself, dump it. These are alternatives : https://alternativeto.net/software/downloadhelper/?platform=linux

Research reviews /feed back/help comments for programs.