I developed a project one year ago in
Already face same issue...
I think you have problem with your splash screen.
Do as follow, it will definitely solved your issue.
1 ) Remove your splash screen from Project.
2 ) Add splash screen using
3 ) Do following setting if require.
Go to -> Project setting - > app icon and launch image -> In source set it to you asset file and also name below
So, I am sorry to say this is not an issue of XCode 8.0 or Swift 3.0
Note: Your problem is in your project you have not include splash screen for iPhone 6. You can directly add the splash screen for iPhone 6