Also getting this, allowed through both the firewall and antivirus.
You are replying to a post from last year, if you checked the sticky thread on the top of this section, it has been reported that lots of users fixed the Live update not starting by installing the new FSDT Universal Installer, which even if it can't install FSX/P3D products (not required, since their installers are always freely available), it can be used as an updater. In fact, it's the new version of the updater, just running with a different interface, when started from the FSDT Installer icon.
It's possible that just installing the Universal Installer might fix something problems you had in your system which prevented the updater from running, since the installer install and registers some required libraries which might have ended up missing/corrupted on your system.