 <p>I had this problem with a project that I've been working on for years, using Xcode 7.3. But one of my colleagues, who cloned the same Xcode project, doesn't have this problem. After trying several different approaches, I downloaded the development certificate from Apple Developer and installed them manually. It works all of a sudden. My guess is Xcode 7.3 messed up with the automatic "fix the problem" feature. </p>