MacOS app does not run on the Xcode simulator

Question

I\'ve installed Xcode 4.2.1 on Mac OS X Lion.

When I create a new (Mac OS X Cocoa) project and I click \"Run\", Xcode says build succeeded, but does

Answer 1

I messed up my settings and had this same issue - builds the app but doesn't launch (either in the simulator or the device).

The answer Product > Edit Scheme got me half way there - then choose Run {your app} on the left. There is a launch Automatically radio button to check: