dyld: Library not loaded: @rpath/libswiftCore.dylib

Question

I am trying to run a Swift app on my iPhone 4s. It works fine on the simulator, and my friend can successfully run it on his iPhone 4s. I have iOS 8 and the official release

Answer 1

This error message can also be caused when upgrading Xcode (and subsequently to a new version of Swift) and your project uses a framework built/compiled with an older/previous version of Swift.

In this case rebuilding the framework and re-adding it will fix the problem.