Add-AppxPackage: Invalid data. (0x8007000D) when packaging standalone executable

I'm trying to package doxygen to be distributed in the Microsoft Store, but I'm having trouble converting the app manually. (Doxygen is as simple as it gets, 4 file: 3 .exe and 1 .dll) I wanted initially to just export the the most frequently used console entry point: doxygen.exe. This is my manifest.

I'm following the docs found here. Everything is fine up until the last step, testing before packaging via

Add-AppxPackage -Register AppxManifest.xml

which results in an error

Add-AppxPackage: Invalid data. (0x8007000D)

My package folder layout is as follows after generating priconfig.xml and resources.pri:

The app manifest is the following (with my publisher ID removed):

<?xml version="1.0" encoding="utf-8"?>
<Package
  xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10"
  xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10"
  xmlns:uap3="http://schemas.microsoft.com/appx/manifest/uap/windows10/3"
  xmlns:desktop="http://schemas.microsoft.com/appx/manifest/desktop/windows10"
  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities">
  <Identity
    Name="XYZ.DoxygenUnofficial"
    Version="1.8.18.0"
    Publisher="CN=..."
    ProcessorArchitecture="x64" />
  <Properties>
    <DisplayName>Doxygen (Unofficial)</DisplayName>
    <PublisherDisplayName>XYZ</PublisherDisplayName>
    <Description>Doxygen is the de facto standard tool for generating documentation from annotated C++ sources, but it also supports other popular programming languages such as C, Objective-C, C#, PHP, Java, Python, IDL (Corba, Microsoft, and UNO/OpenOffice flavors), Fortran, VHDL and to some extent D.</Description>
    <Logo>Assets\doxygen.png</Logo>
  </Properties>
  <Resources>
    <Resource Language="en-US" />
  </Resources>
    <Dependencies>
      <TargetDeviceFamily
        Name="Windows.Desktop"
        MinVersion="10.0.17763.0"
        MaxVersionTested="10.0.18335.0" />
    </Dependencies>
    <Capabilities>
      <rescap:Capability Name="runFullTrust"/>
    </Capabilities>
  <Applications>
    <Application
      Id="DOXYGEN"
      Executable="VFS\ProgramFilesX64\Doxygen\bin\doxygen.exe"
      EntryPoint="Windows.FullTrustApplication">
      <uap:VisualElements
        DisplayName="Doxygen"
        Description="Command-line interface"
        Square150x150Logo="Assets\icon.png"
        Square44x44Logo="Assets\small_icon.png"
        BackgroundColor="#234ea6" />
      <Extensions>
        <uap3:Extension
          Category="windows.appExecutionAlias"
          EntryPoint="Windows.FullTrustApplication"
          Executable="VFS\ProgramFilesX64\Doxygen\bin\doxygen.exe">
          <uap3:AppExecutionAlias>
            <desktop:ExecutionAlias Alias="doxygen.exe" />
          </uap3:AppExecutionAlias>
        </uap3:Extension>
      </Extensions>
    </Application>
  </Applications>
</Package>

What am I doing wrong? Can I get a more meaningful error?