MicrosoftJohn, are you confirming that it fails BOTH if you try to run a .wsb file and ALSO if you just run it via the Windows Start menu shortcut for it? And though it shouldn't be needed, what if you right-click that shortcut and run it "as administrator"? BTW, that shortcut ends up running WindowsSandbox.exe, as found (by default) in C:\Windows\System32\. What happens if you run that directly?
I have not heard of any more useful debugging techniques for when it won't launch, the way you describe. Since it shows the splashscreen, it surely seems that the process is running. It would seem some lower-level problem, perhaps even something about permissions. Or someone might well have you dig more into hyper-v, like you mentioned.
I will just say that it IS running fine for me on all systems I have (several), including ones running the exact same Windows update level you indicate. So it is indeed "nice to have" software that does in fact "work". I've never had it fail the way you describe, nor have I seen anyone else report it--but certainly some could have, somewhere. I hope someone who recognizes the problem or knows more about debugging it may reply. I just wanted to offer what little I could here, especially the opening paragraph, if it may help.
