Question: My app keeps crashing, when I set more than one view controller in my app, like below.

```
[self setViewControllers:_images direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:NULL];

```

My images is an array of view controllers.

The app crashes saying the following error. I have no idea where to start.

```
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'The number of view controllers provided (9) doesn't match the number required (1) for the requested transition

```

Answer: 
As the error says,you are providing more view controllers than needed. You should provide only 1 view controller in an array. Then use page view controller's dataSource methods to provide before and after view controllers properly.
UIPageViewController in iOS has some bugs.
Use UIScrollView + NSArray of UIViewController instead!
Maybe this will help.
<http://weijun.me/post/develop/2015-11-26>