Maui-Blazor-Hybrid-Web app - Web Client - Reports error with code 4294967295 [closed]

I have created a Maui-Blazor-Hybrid-Web app using Visual Studio 17.14.2, It is called MauiBlazorHybridWeb3 and it as simple as I can make. It all works except when I set MauiBlazorHybridWeb3.Web.Client as the start up. When it runs the Output window shows this message…The program '[11456] dotnet.exe' has exited with code 4294967295 (0xffffffff).Nothing appears on the screen.
When I created a simple web assembly app, the start-up screen appeared OK. I expect the Maui app to show the same screen as the web assembly app. What am I doing wrong?