Cannot get Blazor running with VS 2019 preview and 3.0 SDK

Question

I've seen all of the earlier posts (from last year) about global.json and the net core SDK but I just don't seem to be able to get the basic Blazor template project running with either 2.1 or 3.0. I have Visual Studio 2019 Preview 16.0 Preview 3 and 3.0.100-preview-010184 installed. The error is the well discussed HTTP 502.5 Process Failure.

Answer 1

Nicely explained with workaround in Exploring Blazor with Visul Studio 2019.