安装完xcode6.1后，将其改名为Xcode6.1.app，再移动个位置，启动模拟器，问题来了：
Unable to boot device in current state: Creating
解决办法：
You will need to delete this device from your simulator and recreate it.
From inside the iOS Simulator application menu, choose Hardware > Device > Manage Devices
In the Simulators list on the left, select the device that is unable to boot and press the delete key
Now use the + in the bottom left to add a new device with the same hardware / OS configuration.
转自 http://stackoverflow.com/questions/26480836/unable-to-boot-device-in-surest-state-creating
另外还需注意：
Xcode->Preferences->Locations->Command Line Tools的位置重新选择下