Can't launch my app in Instruments: At least one target failed to launch

Edit the scheme for your target and under "Profile [App Name]" set the Build Configuration to Debug (it's usually Release by default).

It is saying that you need to sign the app with a developer certificate (not a distribution certificate).

In Xcode 5 just change the "Provisioning Profile" field for your "Release" build in the Build Settings to your developer certificate instead of your distribution certificate. For the duration of the testing anyway. Xcode doesn't allow you to build with a distribution certificate.

Make sure that the project build settings do not override the target build settings or make the change in your project build settings.

Don't forget to set the profile back after you're done with the testing.

I do not recommend harrywynn's method, since it is better to profile the release build because then you are taking into account the compiler optimizations, and having the exact experience your users will.

To add to the previous answers.

• Instruments is complaining about the signing identity.
• I believe it is preferable to profile in release mode, for the same reasons given by Zolten. (take into account the compiler optimizations, and have the exact experience your users will, etc...)
• To change your code signing identity for Xcode 6:
  • Click on your Project, Select the Target you are Profiling.
  • Build Settings -> Code Signing -> Code Signing Identity -> Release
  • Select your iOS developer profile.
• Provisioning Profile: Let Xcode pick the correct Provisioning Profile for you, e.g: switch to Automatic
• When you are done with the Profile, switch back to your normal settings.

Here's a picture for those who are very visual ;)