Swift: Thread 1 signal SIGABRT

Question

After upgrading Xcode from 5 to 6 beta, almost every project gives me an unexpected error after running the application. There are some other posts with this title but the error

Answer 1

I found this issue happened when I linked @IBOutlet/@IBAction and the linkage broke (renaming for instance). In the main.storyboard inspector, right click (control click) on the elements and delete any bad linkages. Should fix the error if that's the issue.

(Xcode 7)