I have uploaded the iOS App to test flight and have received this email from itunes from xcode 8.0
Invalid sdk value - The value provided for the sdk portion of LC_VERSION_MIN_IPHONEOS in ABC.app/PlugIns/ABC WatchKit Extension.appex/ABC WatchKit App.app/ABC WatchKit App is 8.2 which is greater than the maximum allowed value of 10.3.
Have already validated App deployment version is set to iOS 8.0 while for watchkit Extension its 8.2, the same was working in last release, as there where have not been any changes, not sure what the issue.
Can it be due to iOS 10.3 been recently released some how its restricting any upload to test flight.