Since I've decided to retire my old WHS machine running WHS v1 I'm running some basic tasks on 2012 r2 machine (not OEM version, since I'm pretty much using this for my own home business and backing up all the machines in my household). Anyway to cut to the chase I have this issue with media streaming, I stopped a long time ago to fix this issue with remote streaming, it's just not working, why, who knows, but now I have similar issue with streaming in local network between my other machines.
This was working before, now it has same result as you are trying to stream outside the home network, window pops up and player just going round and round, any suggestions?
Also I had similar problem when media tab just disappeared from settings page and it took me some time to find out what it was.
Since I'm using Samsung SSD as primary boot disk I find out as soon as I install Samsung Magician media pack stops working, tab disappeared from settings page and only solution was to remove Samsung SSD tool and reinstall media pack. Maybe some of you find this helpful.