[Bug]: Windows Sandbox Doesn't Open

[JustAT0rtoise]

Windows Sandbox version

10.0.26100.7019

Windows build number

10.0.26200.7171

Other software

No response

Steps to reproduce the bug

1. Enable Windows Sandbox through "Windows Features."
2. Restart PC
3. Attempt to open Windows Sandbox

Expected result

For Windows Sandbox to open and work.

Actual result

Upon the first launch, I get the popup for "Downloading and installing updates...". It then closes after a few seconds, and nothing happens after that.

Included System Information

-- EVENT VIEWER ERROR 1 --

Description: The process was terminated due to an unhandled exception.
Exception Info: System.TypeInitializationException: The type initializer for '' threw an exception.
---> System.IO.FileNotFoundException: Could not load file or assembly 'WinRT.Runtime, Version=2.2.0.0, Culture=neutral, PublicKeyToken=99ea127f02d97709'. The system cannot find the file specified.
File name: 'WinRT.Runtime, Version=2.2.0.0, Culture=neutral, PublicKeyToken=99ea127f02d97709'
at WinRT.WindowsSandboxRemoteSessionGenericHelpers.GlobalVtableLookup.InitializeGlobalVtableLookup()
at .cctor()
--- End of inner exception stack trace ---

-- EVENT VIEWER ERROR 2 --

Faulting application name: WindowsSandboxRemoteSession.exe, version: 0.5.3.0, time stamp: 0x684a0000
Faulting module name: KERNELBASE.dll, version: 10.0.26100.7171, time stamp: 0xb1a43a46
Exception code: 0xe0434352
Fault offset: 0x00000000000c80da
Faulting process id: 0x68E4
Faulting application start time: 0x1DC659E1DD589D4
Faulting application path: C:\Program Files\WindowsApps\MicrosoftWindows.WindowsSandbox_0.5.3.0_x64__cw5n1h2txyewy\WindowsSandboxRemoteSession.exe
Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll
Report Id: c9201954-67ed-40a9-bff1-833648a8e0b2
Faulting package full name:
Faulting package-relative application ID:

[the-P1neapple]

Can you try running again as Admin?

I had the exact same problem and this seemed to do the trick.

[JustAT0rtoise]

Can you try running again as Admin?

I had the exact same problem and this seemed to do the trick.

I could've sworn I tried that before, and it didn't work, but right now I just enabled Windows Sandbox after having it disabled ever since this issue, ran it as Administrator, and now it works.

Thanks, I guess this is the temporary resolution to this problem?

[kkm000]

The MSIX package is borked: files WinRT.Host.dll and WinRT.Host.dll.mui are missing. procexp shows that the file WinRT.Host.dll is attempted to load and isn't found. Since you welded the hood of the car OS that I own using your crappy creeping PsProtectedWindowsSigner-Light, as if Solitaire and other those horrific Store "Apps" were security-sensitive Windows components, I cannot confirm that these are the only files missing. Dunno whom am I talking to — no one monitors this repo anyway… Five months!

PS> gci "C:\Program Files\WindowsApps\MicrosoftWindows.WindowsSandbox_0.5.3.0_x64__cw5n1h2txyewy"\*winrt*
    Directory: C:\Program Files\WindowsApps\MicrosoftWindows.WindowsSandbox_0.5.3.0_x64__cw5n1h2txyewy
Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a---            26-04-18    17:11          17952 WinRT.Host.Shim.dll
-a---            26-04-18    17:11           4096 winrt.projection.dll
-a---            25-01-31    11:38         528944 WinRT.Runtime.dll