Installed App from TestFlight crashes due to alleged UISearchDisplayController

Question

I implemented Dark Mode with the current beta version of Xcode in a relatively old app. I uploaded these to TestFlight for my testers. However, this crashes immediately for

Answer 1

It was working on simulator but all beta tester claimed it crashed. The problem was in story board. Search for these in your views.

Answer 2

After receiving the same error and finding no references to UISearchDisplayController across our app, we realized we needed to search for and replace searchDisplayController from within one of our storyboards. That corrected the issue after resubmitting a beta to TestFlight.