Searching for iOS 6.0 Headers

Switch to: 17.1, 16.3, 15.2.1, 14.4, 13.1.3, 12.1, 11.1.2, 11.0.1, 11.0, 10.2, 10.1.1, 9.3.3, 9.0, 8.0, 7.0, 5.0, 4.0, 3.0

Error resolving file.