title: Yosemite ios 6.1 simulator can not launch?
body: <p>I use the Yosemite Xcode 5.1.1 to test my project ,in 7.1 simulator is ok ,but can not test it in 6.1.1 simulator ,  every time show a alert ios simulator failed to install the application. even reset the simulator , can not launch. anyone can help me solve it ?</p>