I am trying to rebuild an ios app, that previously had no issues (first rebuild in 6 months or so). Environment is OSX 10.13.5 with all the latest updates, Xcode 9.4.1, Ionic is
What fixed it for me was plugging my iPhone and allowing it as a simulator destination. Doing so required my to register my iPhone in Apple Dev account and once that was done and I ran my project from Xcode on my iPhone everything fixed itself.