OK, so I have tried everything possible but still having issues.
I am testing on two devices. An iPhone and an iPad. When I connect the iPhone to Xcode and hit run
In order to fix this problem, please follow these steps:
I. Go to Xcode Settings (Xcode -> Preferences), and select "Accounts." Make sure you are signed in to your developer account.
II. Click on the first tab under the run button, and then click on the name of the project (circled in red)
III. Under "Identity" select the account that matches your build identifier, or click "Fix Issue"
IV. If this does not fix your issue, go to "Build Settings" -> "Code Signing"
V. Finally: If this does not fix your issue, go back to the Certificate Center in the iOS Developer Center (developer.apple.com) and reprovision the certificate, then repeat these steps.