HEADS UP FOR AD HOC DISTRIBUTION:
If OS 7.1 has been installed on any devices that are testing apps via ad hoc distribution, they will fail with a “certificate error” when attempting to download.
The “certificate” is not the app’s .cer certificate, but one on the server hosting the download location.
OS 7.1 requires that ad hoc apps be downloaded via “https://…” locations.
A “Secure Server Certificate” is required.
Hope this helps anyone that is having an issue with ad hoc app distribution.