I installed macOS Catalina Beta 3 today and also the latest Xcode 11 beta. I launched Xcode 11, opened the FreelanceStation project, and then hit Cmd+B to build it. The build failed with an error indicating Xcode couldn’t open a particular storyboard. I first thought the new Xcode was the problem, but it also happened with version 10. So I opened the storyboard as source code and started cutting pieces of it until Xcode was able to open it in IB mode.