To Reproduce:

1. Build & run the attached project for Apple tv (use Xcode 7.2).
2. Observe that you'll get the errors from the comment below.

When building with Xcode 7.1.1, the icons and splashes catalogs are still colored red in build settings and after clicking on Images.xcassets folder you'll get this popup:

"Migrate Apple TV app icons?
The format of Apple TV app icons within asset catalogs has changed. Would you like to migrate the Apple TV app icons in this catalog to the new format?"

But the project can still be built.

Removing or manually setting up icons in Xcode solves this error.