My previous attempt at running the command line execute failed due to omitting the quotes from the command. I re-ran it today, again the program launch was unsuccessful, but I did get a more meaningful log.txt file:

Exception in thread "main" java.lang.UnsatisfiedLinkError: no JavaAccessBridge-64 ...

Here's the log.txt file:
'SweetHome3D.exe' is not recognized as an internal or external command,
operable program or batch file.

Yes SweetHome3D.exe exists in the WindowsApps folder, just where you said it would be. No there is no Java process running.
I also downloaded SweetHome3D-6.4.2-windows.exe from SourceForge and installed it. It does not run either.
Both give me the same result, i.e. nothing. No error msgs or anything.

Thanks for the reply. This is frustrating that I can't get SH3D to launch. I had great success a few years ago with an earlier version, and a different laptop, but now I get nothing!

The link you provided did not work. It returned an error msg saying the server can't be reached. However I went to ...

I just bought the SH3D app from the microsoft app store and installed it under Win 10. It seems to have installed OK, but it will not open. I have tried rebooting my machine, but there is no change.

I am running Win 10 Home version 1909 (build 18363.959).

Not sure what options I have now, other ...