Unreal Engine 4 is available for Win10 UWP app dev now

0 bytes for xboxservices.config is not a good sign. Does your output by any chance contain an error something like “Xbox Live Title Id was not in a recognized format. Specify a 32 bit hex number (without leading 0x)”? As for the Appx/Engine folder, that is created as part of the Visual Studio Deploy step. Build on its own wouldn’t create one.