For me, the problem was in one of the frameworks that I had added to my workspace and not in my primary project. Specifically, I was using the Split.io framework version 2.13.0. Looking at the Build Phases of the framework, the sequence was Dependencies Compile Sources Link Binary With Libraries Headers Copy Bundle Resources Changing it to have the Headers step earlier, like this, fixed the problem for me. Dependencies Headers Compile Sources Link Binary With Libraries Copy Bundle Resources This problem is also fixed in Split framework version 2.16.2. Updating to this latest release is probably the easiest way to fix the problem.