Code Sign error: The identity 'iPhone Developer' doesn't match any valid certificate/private key pair in the default keychain

Question

How do you fix this XCode error :

Code Sign error: The identity 'iPhone Developer' doesn't match any valid certificate/private key pair in the default keychain

Answer 1

This happens if you forgot to change your build settings to Simulator. Unless you want to build to a device, in which case you should see the other answers.