IIS .Net MVC HTTP Errors

I was setting up a new IIS server yesterday to host a .Net MVC app and got the usual string of errors including but not limited to:

• Invalid/Cannot read config file
• HTTP Error 403.14 - Forbidden
  The Web server is configured to not list the contents of this directory.

Here is a good post on a couple of other requirements of MVC on IIS but what it fixed it for me was much more basic: It was a legacy bit of code in it's own directory that originated elsewhere and so of course didn't have the local computer's necessary IIS_IUSRS permissions on the folder and it's contents. This has caught me out before so I'm posting it here as a reminder.

In Explorer, right click, Properties, Security tab, Edit, ensure the 'search for objects from' selection is set to local computer then enter the user IIS_IUSRS and ensure at least:
Read and execute
List folder contents
Read