crashing on/shortly after Unity Splash on Windows Builds.

I have an app that crashes on Windows 8.1, Windows 10, and Windows Phone 8.1.

The editor shows no Errors(the project is fine), C# compiler gives no errors, and building the app package gives no errors.

However, on all Windows devices the game gets stuck at the Unity Logo, flickers black and white. ("development build still shows in corner") I have built the project as WP8, and Windows 8.1 Universal and each exhibit the same behavior.

Does anyone know what this signifies? or how to fix? The game has been deployed to several devices over the past 6 months just fine -- but not now.