Windows Sandbox fails with error 0x80070002

Question

Windows Sandbox won't start. When I launch it I get this:

I have a suspicion it may be because I have uninstalled Microsoft Edge. (Please note that this was a legitimate uninstallation, the functionality is offered to all EU residents and does not involve third-party tools or any "hacking".) The two shouldn't have any reason to rely on each other but it worked fine on my device until I removed Edge.

Is there a custom WSB or something I can use to bypass the requirement for Edge? Sandbox is not worth installing Edge for so I am hoping there is a happy medium I can strike.

Answer 1

Another cause of this (exactly the same) error is when you've got mapped Host-folders in your *.wsb that don't exist.

The Windows Sandbox documentation mentions this: https://learn.microsoft.com/en-us/windows/security/application-security/application-isolation/windows-sandbox/windows-sandbox-configure-using-wsb-file#mapped-folders but man is that a cryptic error message. Microsoft could have at least provided the name of the missing "file".

Answer 2

Thanks to Albin.
The solution is to reinstall Microsoft Edge (from here) – click "Download anyway" – and let it install. Then, with Sandbox already installed, launch it and you'll see that it works fine.
From here, with Sandbox still running, close and proceed to uninstall Edge again. Whatever Sandbox needs to continue working will be spared from the uninstallation process and you get to have your cake and eat it too.

I'd recommend using a launch script in a WSB file to install Firefox as the first step.

(Edit: This stopped working for me after a few reboots. YMMV. The eventual "fix" ended up being to install Edge and just forget about it.)