HTML5 and latest preview problems

hello
seems sometimes there is a better response from the forum than answers so here it is.
heres the answers post https://answers.unrealengine.com/questions/82422/emscripten-sdk-found-but-of-unexpected-version-ple.html

the only reason to build the engine from source for me is HTML5, for some reason version 4.2 i had built crashes whilst packaging (worked before) so i downloaded the latest preview from github.

whilst building in visual studio it gives this warning (also possibly when generateprojectfiles.bat is going)

looking at emscripten there seems to be no way to specify a version.

after the engine has built, the package HTML5 option has completely gone from the frontend.
this option is there in the editor but brings up a window with links to tutorials ect.

anyone experienced this?
any fixes?

thanks