Debugging Classic Projects on the CLR
On Windows, (non-Core) .NET projects by default will run on Microsoft's Common Language Runtime (CLR), which ships preinstalled with every version of Windows since Windows XP Service Pack 2.
No additional setup steps should be needed on most systems, but you can install additional, older or newer versions of the .NET Runtime and the CLR, as needed. The latest (and last) version of the CLR is .NET Framework 4.8.
The IDEs will automatically find the best installed version of the CLR for you.
Note that on Mac, debugging always uses the Mono Runtime, instead.
Launching
Both Water and Visual Studio will automatically use the Common Language runtime for launching (non-Core) .NET projects on Windows. (In Water, you can choose between using Microsoft's Common Language Runtime or Mono, by setting the Debug Engine in Project Settings to CLR (the default) instead of Mono.)
Debugging
Once your your application is launched, you can debug your code the same as you would any other project. For example, you can set Breakpoints to pause execution when a certain part of your code is hit, and you will automatically "break" into the debugger, if any Exception occurs.