Cocoa Programming for OS X (5th Ed) book

I’m running XCode 10.1 and MacOS 10.13.6.
Build and run doesn’t show the MainWindowController.
Why?

Can you post your code?

I sent you my code. Did you get it?

My understanding is (middle of pg. 17) … command R should show the user interface (pg. 13). That didn’t happen for me … what did I do wrong, please?

You can post your code here so that others also can see it.