This type of error occur when i install SDK 3.2.5 ios 4.2 and run my older project…
older project run successfully in previous version of Xcode…
Code Sign error: The identity ‘iPhone Developer’ doesn’t match any valid certificate/private key pair in the default keychain
Go the your project on the left(Groups & files column), right click on it and select get info.
Go to build tab and look for code signing. Under the code signing identity, make sure you select the correct development profile.