There several things wrong in your screenshot, your installed seems to be an old version, since it doesn't have the icons to show/hide MSFS or FSX/P3D product and this, added with the fact is not downloading files which are surely online, seems to indicate a problem caused by an antivirus or a firewall blocking the downloads and preventing to get the correct version.
- Configure the antivirus to add the whole Addon Manager folder to the antivirus EXCLUSIONS.
- Be sure you don't have a firewall that might block downloads
- Download and install the current version of the FSDT Universal Installer.