iPhone: Failed to launch simulated application: Unknown error

Question

This is a new iPhone project, only 1 target (different from this question)

On build we get:

Failed to launch simulated application: Unknown error.
         


        

Answer 1

This happened to me once and I think I saw in a blog to simply quit and restart Xcode. Miraculously, it worked for me. I doubt this is the end all solutions to all problems like these though, but if you haven't yet closed Xcode, it's worth a try.