About the update error, we finally found what the cause was and, as usual, it didn't depended from us...
The Live Update feature relies on TWO servers running on two different hosts, in order to make it more reliable in case one of them might be down. The servers are chosen at random, at each start of the updater.
Since a couple of days, ONE of the two servers was down so, all you that got that error, was because the randomly ( 50% chance, since there are two of them ) selected server was the one that was down.
The reason why it was down is because, due to the famous Heartbleed web vulnerability, that affected almost every server out there, the ISP disabled all our shared links, but of course they didn't say anything about it. It was only after asking for support, that we discovered the problem.
In the meantime, we moved to a different server, but in order to get the updated "updater" program ( the Couatl_Updater.EXE ) which knows about the new server, you need to download the STAND-ALONE ADDON MANAGER installer, and install that one. It will BOTH Update whatever you had to update in the Live Update, and will update the updater program too, so you shouldn't see any connection errors anymore.