[Bug]: Crashes on startup with "Element not found. (0x80070490)"

[DandelionSprout]

Windows Sandbox version

0.5.3.0

Windows build number

10.0.26200

Other software

None that seem relevant to this.

Steps to reproduce the bug

1. Enable the Windows Sandbox feature with e.g. Enable-WindowsOptionalFeature -FeatureName "Containers-DisposableClientVM" -Online
2. Launch Windows Sandbox.
3. On launch, it will take some seconds to attempt to install updates for itself.
4. Sandbox then fails to launch, showing a prompt window that says "Error — Windows Sandbox failed to initialise/initialize. Element not found. (0x80070490)", and its only option is "Close".
5. Close Sandbox.
6. Try to open Sandbox again.
7. Sandbox crashes near-instantly with the same prompt.

Expected result

Windows Sandbox starts up correctly.

Actual result

Included System Information

• OS: Windows 11 Pro for Workstations 25H2 x64, with all monthly OS updates through May 2026 installed.
• GPU: Nvidia 3060
• CPU: AMD Ryzen 3600
• RAM amount: 48 GB DDR4
• Disk space: 〜1.5 TB
• OS locale: en-GB while taking the screenshot above; otherwise usually nb-NO.