Visual Studio automatically applies the exception when running under the debugger. There’s a similar step in the AutomationTool implementation for UWP - see the end of UWPPlatform.Deploy.
I haven’t looked at the actual project, but if you’ve got past the UWP splash screen and onto a black window then you’ve loaded something, probably the built-in Entry map. You might see whether you can open the debug console and load some other map, or take a look at the debug spew to see if it offers any clues.