I just download recent version of Blazor, and create new project using your extension. After running it, there was clearly something missing, as Grid controll was not looking great.
I then realize, that your software added link to css file:
but when you are trying to open it, it says access denied.
After changing this line to local bootstrap4 css, then it all looks good.
I haven't change anything, just create project using your extension (blazor WASM with ASP.NET hosting).