Works fine with Xcode 4.5.
Steps To Reproduce:
1. Create a default project.
2. Run project in iOS simulator
[ERROR] : An error occurred running the iOS Simulator
[ERROR] : [DEBUG] Session could not be started: Error Domain=DTiPhoneSimulatorErrorDomain Code=1 "iOS Simulator failed to install the application." UserInfo=0x101a0f2a0
[ERROR] : Project failed to build after 21s 304ms
Project must launch successfully in simulator.
Deleting files from /Users/pragya.rastogi/Library/Application Support/iPhone Simulator/6.1/Applications resolves the issue temporarily.
'iOS Simulator > Reset Content and Settings...' works as well.