I created simple node.js application (source code from here https://azure.microsoft.com/en-us/blog/visual-studio-code-and-azure-app-service-a-perfect-fit/)
var h
The error should ideally read 'file specified in program attribute does not exist' because that is what is happening. As of VSCode 1.30.2, it does show you the path along with the error.
In my case I had
"program": "${workspaceFolder}\\${file}"
so the path was something like c:\dir\c:\dir\file.js
I corrected this by removing ${workspaceFolder}
since I wanted to be able to debug individual files.