Unable to boot device in current state: Booted

Any guess on "Unable to boot device in current state: Booted" error in Xcode6 beta while running (build+run) project in Simulator. I am just running my existing project in Xcode 6 I found above message. I tried cleaning, deleting of the derived data, even restarting the simulator doesn't work. Finally i restarted my Xcode 6 then it is working. Any simpler way to resolve the error instead of restarting your xcode6.

In Xcode go to the Xcode menu->Open Developer Tool - IOS Simulators. Choose simulator and then go hardware->device->manage device.

If the troubled device shows in the left column, delete it. Then add the device back from the '+' button. If it wasn't there in the first place, simply add it using the '+' button.

From terminal, get the list of devices with:

xcrun simctl list

This will show you your list of devices with "Shutdown" or "Booted". You'll likely see your device is in a "Booted" state. You can shut it down with:

xcrun simctl shutdown <simulator id>

Where <simulator id> is the name of the device in the list. For example:

xcrun simctl shutdown "iPhone 6 Plus"