I have this issue with two projects now since build 195 and current build 198.
I export to Windows 8.1 (vs 2013). The app works on my x64 system when I test. Submit and everything passes certification.
On Windows RT systems, the app launches, goes to the splash screen, then closes, so it never really gets into even the first layout of the game. Works just fine on x86 and x64.
I'm not sure if this is a bug, user error, or whatever, but I just released an update on my bestselling app and basically broke it (for some systems).
Does anyone have any ideas where to look, is there any logging etc? Any help is appreciated.