The first one is rather obvious; who doesn't look at the browser output? However, for ASP.NET Core applications, it's far less effective than it used to be, since most errors are still unhandled and won't appear there. Since the application is running in Production mode by default, it will hide--for security reasons--most of the error details. That's a common production-level error message that doesn't tell us anything useful:
In order to get a more useful error message, we need to follow the suggestion printed out at the end of the error page and set up the ASPNETCORE_ENVIRONMENT environment variable--which defaults ...
