【Swift】ライブラリ Instantiate を使用した際のエラー "Fatal error: Unexpectedly found nil while unwrapping an Optional value"

エラー

Storyboard+UIViewController.swift

    public extension StoryboardInstantiatable where Self: UIViewController {
        init(with dependency:Dependency) {
            let storyboard = (Self.self as StoryboardType.Type).storyboard
            switch Self.instantiateSource {
            case .initial:

                // ここで落ちた
                self = storyboard.instantiateInitialViewController() as! Self
            case .identifier(let identifier):

                self = storyboard.instantiateViewController(withIdentifier: identifier) as! Self
            }
            if self is ViewLoadBeforeInject {
                _ = self.view
            }
            self.inject(dependency)
        }
    }

解決策

Storyboardの Is Initial View Controller にチェックをする。