ExtendedSplashScreen throws exception running as unpackaged

[nickrandolph]

Current behavior

When running Windows as unpackaged, the ExtendedSplashScreen control throws an internal exception (ie one that is caught) when attempting to load the AppxManifest.xml file (which does exist in the publish folder).

Issue seems to be with the "file:" prefix that's at the beginning of the directory name returned for the executing assembly.
file:\C:\source\github\unoplatform\Uno.Platform\testing\TestHarness\TestHarness.Windows\bin\x64\Debug\net8.0-windows10.0.19041.0\win-x64\AppxManifest.xml

System.ArgumentException
HResult=0x80070057
Message=Value does not fall within the expected range.

Expected behavior

AppxManifest.xml file exists, so this methods should return the correct path to the corresponding file.

How to reproduce it (as minimally and precisely as possible)

Nuget Package:

Package Version(s):

Affected platform(s):

• WebAssembly
• Android
• iOS
• macOS (AppKit)
• Mac Catalyst
• Skia
  • WPF
  • GTK (Linux)
  • Linux Framebuffer
  • Tizen
• Windows

IDE:

• Visual Studio 2022
• Visual Studio 2019
• Visual Studio Code
• Visual Studio for Mac
• Rider Windows
• Rider macOS

Relevant plugins:

Anything else we need to know?

System.Private.CoreLib.dll!System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() Line 53	C#
System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(System.Threading.Tasks.Task task) Line 154	C#
System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(System.Threading.Tasks.Task task, System.Threading.Tasks.ConfigureAwaitOptions options) Line 118	C#
System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter<System.__Canon>.GetResult() Line 335	C#
[Waiting on Async Operation, double-click or press enter to view Async Call Stacks]	

Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.ApplicationPathFromFileName(System.Reflection.Assembly entry, string fileName) Line 300 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.LoadManifestFromPackageFile(System.Reflection.Assembly entry, string manifestFile) Line 247 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.LoadAppManifest(System.Reflection.Assembly entry, string[] manifestFiles) Line 228 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.LoadSplashScreenFromPackageManifest(Microsoft.UI.Xaml.Controls.Image splashScreenImage, Microsoft.UI.Xaml.Media.SolidColorBrush splashScreenBackground) Line 196 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.GetNativeSplashScreen() Line 130 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.LoadNativeSplashScreen() Line 85 C#
Uno.Toolkit.WinUI.dll!Uno.Toolkit.UI.ExtendedSplashScreen.OnApplyTemplate() Line 79 C#
Microsoft.WinUI.dll!Microsoft.UI.Xaml.FrameworkElement.Microsoft.UI.Xaml.IFrameworkElementOverrides.OnApplyTemplate() Unknown
Microsoft.WinUI.dll!ABI.Microsoft.UI.Xaml.IFrameworkElementOverrides.Do_Abi_OnApplyTemplate_2(nint thisPtr) Unknown
[Native to Managed Transition]
[Managed to Native Transition]
Microsoft.WinUI.dll!ABI.Microsoft.UI.Xaml.IFrameworkElementOverridesMethods.MeasureOverride(WinRT.IObjectReference _obj, Windows.Foundation.Size availableSize) Unknown
Microsoft.WinUI.dll!Microsoft.UI.Xaml.FrameworkElement.MeasureOverride(Windows.Foundation.Size availableSize) Unknown
Microsoft.WinUI.dll!Microsoft.UI.Xaml.FrameworkElement.Microsoft.UI.Xaml.IFrameworkElementOverrides.MeasureOverride(Windows.Foundation.Size availableSize) Unknown
Microsoft.WinUI.dll!ABI.Microsoft.UI.Xaml.IFrameworkElementOverrides.Do_Abi_MeasureOverride_0(nint thisPtr, Windows.Foundation.Size availableSize, Windows.Foundation.Size* result) Unknown
[Native to Managed Transition]
[Managed to Native Transition]
Microsoft.WinUI.dll!ABI.Microsoft.UI.Xaml.IApplicationStaticsMethods.Start(WinRT.IObjectReference _obj, Microsoft.UI.Xaml.ApplicationInitializationCallback callback) Unknown
Microsoft.WinUI.dll!Microsoft.UI.Xaml.Application.Start(Microsoft.UI.Xaml.ApplicationInitializationCallback callback) Unknown
TestHarnessApp.dll!TestHarness.Program.Main(string[] args) Line 32 C#