UE4 4.5 cannot launch to HTML5

yes i tried to build the project directly to HTML5 from VS but it ends up saying " there is no UE4Game.exe " (note the exe extension). i do not have the exact log since i got frustrated and deleted the whole thing. Now i am thinking on building a virtualbox image to share so you can test there. come to think about, it should be provided by Epic so we can focus on the game itself.