Steps to reproduce (VS 2017):
- Create a new ASP.Net webservice
- Set the generated asmx as startup
- Place a breakpoint on the Exit “Hello world” line
- Start the debug session
- Execute the method from the browser - the breakpoint is not hit.
Further information: the breakpoint is invalid after run because no debug information is available:
Edit: Open the webservice and attach the debugger to it has the same effect.