Error on performSegue to UIPageViewController - ios

Question

I'm trying to performSegue() with an animation from left:
class SegueFromLeft: UIStoryboardSegue {
override func perform() {
let src = self.source
let dst = self.destination
src.view.superview?.insertSubview(dst.view, aboveSubview: src.view)
dst.view.transform = CGAffineTransform(translationX: -src.view.frame.size.width, y: 0)
UIView.animate(withDuration: 0.25,
delay: 0.0,
options: .curveEaseInOut,
animations: {
dst.view.transform = CGAffineTransform(translationX: 0, y: 0)
},
completion: { finished in
src.present(dst, animated: false, completion: nil)
}
)
}
But somehow I get the following error for this line: src.present(dst, animated: false, completion: nil), when performSegue is being executed:
Thread 1: EXC_BAD_ACCESS (code=2, address=0x16b607fc0)
I can see the animation, but as soon as the new view is being displayed - the app crashes.
PageViewController in case it helps:
class LeasingTutorialViewController: UIPageViewController, UIPageViewControllerDataSource {
lazy var viewControllerList:[UIViewController] = {
let sb = UIStoryboard(name: "Main", bundle: nil)
let vc1 = sb.instantiateViewController(withIdentifier: "leasingPageOne")
let vc2 = sb.instantiateViewController(withIdentifier: "leasingPageTwo")
return [vc1, vc2]
}()
override func viewDidLoad() {
super.viewDidLoad()
self.dataSource = self
if let firstViewController = viewControllerList.first as? LeasingPageOneViewController {
self.setViewControllers([firstViewController], direction: .forward, animated: true, completion: nil)
}
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let vcIndex = viewControllerList.firstIndex(of: viewController) else { return nil }
let previousIndex = vcIndex - 1
guard previousIndex >= 0 else { return nil }
guard viewControllerList.count > previousIndex else { return nil }
return viewControllerList[previousIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let vcIndex = viewControllerList.firstIndex(of: viewController) else { return nil }
let nextIndex = vcIndex + 1
guard viewControllerList.count != nextIndex else { return nil }
guard viewControllerList.count > nextIndex else { return nil }
return viewControllerList[nextIndex]
}
}
Edit:
It's called in a different ViewController ("goToLeasingTutorial") under some conditions:
Another important note: As soon as I restart the app, it works fine again.
#IBAction func goToLeasing(_ sender: Any) {
if leasingTutorialSeen == false && leasingInStartScreen == true {
performSegue(withIdentifier: "goToLeasingTutorial", sender: self)
} else if leasingTutorialSeen == true && leasingInStartScreen == true {
buttonHamburgerTapped(self)
let parentVC = self.parent as! RootPageViewController
parentVC.setViewControllers([parentVC.viewControllerList[1]], direction: .forward, animated: true, completion: nil)
} else if leasingTutorialSeen == true && leasingInStartScreen == false {
performSegue(withIdentifier: "goToLeasing", sender: self)
}
}