Xcode will run app on simulator but not on device

Question

I receive the following error when trying to run the app on my device.

error: failed to launch \'/Users/michael/Library/Developer/Xcode/DerivedData/Build/Pro         


        

Answer 1

For me restarting of Xcode, cleaning DerivedData and restaring device wasn't enough in most cases, until I had figured out that iTunes was also running, and after quitting iTunes everything worked fine!

So my steps now are simple:

1. Quit Xcode.
2. If iTunes is running, quit iTunes.
3. Reopen project.

No need to remove app from the device, clean project or restart/disconnect device. I think that's because Xcode and iTunes use some common libraries (as you know, Xcode Installer always asks to quit iTunes on installing iOS SDK).