iOS 8.1 Simulator Failed To Boot

Hi Guys,

I am not able to launch the specified device like ''IPhone 5" or ‘iPad 2’ , unless the device is manually launched. So all my test fails with ''Instruments Crashed on Startup error".

Manually executing the instrument spawning script shows “waiting for device to boot” and it fails.

I believe there is some setting need to be done in my mac, can anyone please support on this.