[4.11P2 Prebuilt][Bug] HTML5 map downloading on the fly is broken. (Plus problems with non-map downloading on the fly on latest firefox)

I used Visual 2015 Community Update 1 and the Windows 10 SDK. The issue persists through 4.11 Preview 5, but I haven’t tried the more recent previews as I have moved on to work on other things. I’ve confirmed that it happens with the tower defense example game as well. It also happens to both and the tower defense game on my laptop.