Xcode Project won't run on iOS Device

Unplugging iOS Device and plugging it back it in fixed it for me.

Alright, it was a simple fix:

1. Go into Xcode Preferences -> Accounts -> More Info. Hit the refresh icon.

2. Clean your project. Project -> Clean.

3. Force quit Xcode.

4. Reboot Mac and Device.

If you have the same App but downloaded from AppStore, I suggest to remove the App manually from your device, then try to run the new version with XCode.