UWP Background Application not deploying (Error DEP0700)

I made a new solution, added two UWP Class Libraries, and a UWP Background Application (from this template package). I'm trying to debug locally and develop the app on my PC before deploying to a Raspberry Pi as I'm still waiting for the RPi delivery. However, when trying to build and deploy the project, I get the following error:

DEP0700: Registration of the app failed. [0x80073CF6] AppxManifest.xml(27,6): error 0x80080204: Cannot register the SHVending.Entry-uwp_1.0.0.0_x86__nn0daenrxbv52 package because the following error was encountered while registering the App activatable class: The Appx package's manifest is invalid. . Try again and contact the package publisher if the problem persists.

I have set the entry point in the app manifest to "SHVending.Entry.StartupTask" (which is the namespace + the startup class). I have also tried just "StartupTask".

If I leave the entry point blank, it seems to build and deploy properly, but then I get the following issue instead

Unable to activate Windows Store App.

I'm building in Debug mode targeting x86 CPU on my Local Machine.

Edit: Just to clarify, the reason it's running on x86 is because Raspberry Pi only support x86.