Error while launching the application on device
First try restarting Xcode. If it doesn't work, then try hard reset of your device.This happens to me when I change the bundle identifier of my app.
With XCode 5 beta, an Hard reset of the device was needed to solve the problem.
What finally fixed it for me was restarting the device (after doing everything else everyone recommends here, here Xcode 4 Error: Error Starting Executable here Xcode suddenly stopped running project on hardware: "Could not launch xxx.app: .. No such file.." and here Xcode Developer Preview: Cannot Run on Device