Xcode 4.3.2, issue with running on simulator

Question

I have been having this weird problem with Xcode 4.3.2, of course after the recent update.

After successfully building and running on the simulator several times, xc

Answer 1

This has frustrated me for -years- now but stumbled across what appears to get things going again for me:

Hide the simulator (iOS Simulator -> Hide iOS Simulator) or Cmd-H, then reopen the simulator.

The problem seems to happen when something CPU intensive is happening in the background (like a Time Machine backup) on my old 2 core MacBook.