ah i figured it out, just set the launch image right in assets.xcassets
1, Select Assets.xcassets select launch image folder.
2, Check "iOS 8.0 and later" in the right Attribute inspector panel.
3, An iPhone X place holder will appear, drag an image 375w812h @ 3x to it and you are done.
You found the solution! We already ship a corresponding launch image for iPhone X in our wizards but do not activate it by default until all of our components are ready for it. So stay tuned for one of the upcoming updates for that!