Just for record, if you download and build source using github, you can download things from marketplace using Unreal Engine launcher, and it shows up when you run version of engine you built.
Not a fix, but definitely an option if you want to start using engine. It took me roughly a couple of hours to install VS 2013, download source and required files, and compile it.
video from Epic with build instructions is located here:
https://www…com/watch?v=usjlNHPn-jo
Additional notes on Subscribe problem:
I installed launcher on another computer aside from my computer. (My is running Windows 8.1 64bit, and other Windows 7 64bit) and I still get same problem.
I think akfish might be onto something when he mentions license authorization servers: It kinda reminds me of ffxiv 2.0 beta toward beginning - tons of people trying to connect, and lots of dropped connections - literally sitting there for 1/2 hour just to login. I also got a “server unstable, click this link to refresh” when trying to view my account on unrealengine.com today, which supports this theory. This is just speculation of course, but I may try to repeatedly logon/off for a bit, just to see if it works. If this is problem, a launcher with a “Refresh Account” button might be useful.