When I try to use Xcode5 dp6 to run app on devices. I got an error of
No Provisioning Profiles with a valid Signing identity found issue
I had exactly the same issue and I manage to sort it by deleting provisioning certificate from Keychain app and I download it again via Xcode (Xcode -> Preferences... -> Accounts). If it doesn't help try remove certificate and provisioning profile. After than make sure you set up everything right in Build Settings (Code signing). Hope this help
You should now be able to select one of the Team Provisioning profiles to run in debug mode.
All you need to do is:
1. go to Certificates, Identifiers & Profiles in the Developer Center
2. create a new provisioning profile in "Provisioning Profiles" / "Distribution"
3. download the profile and open it
4. restart Xcode
And you can take a look at this post, and this and this.