Hmm. I don’t know what is up. You need to address that build error somehow, I bet. Is your Visual Studio 2015 up to date?
I would also make sure that you are really using your version that was built from source. When I was working on this, I removed all my unreal versions from the launcher, and then uninstalled the launcher so I could be absolutely sure that I was using the version I was building.
Make a desktop shortcut that points to the unreal engine in \Engine\Binaries\Win64\UE4Editor.exe so you can run your new version easily.