Problem with page : Multi touch

[HaSyHieu]

I use the Unity Book Page CURL, with more than 2-3 fingers towards all scenes. It turn out that pages go blank and after that, the exception is thrown : ThirdParty.Scripts.BookPro.UpdatePages () (at Assets/ThirdParty/Book-Page Curl Pro/Scripts/BookPro.cs:319)
ThirdParty.Scripts.BookPro.set_CurrentPaper (System.Int32 value) (at Assets/ThirdParty/Book-Page Curl Pro/Scripts/BookPro.cs:100)
ThirdParty.Scripts.BookPro.DragRightPageToPoint (UnityEngine.Vector3 point, System.Boolean pageDragging) (at Assets/ThirdParty/Book-Page Curl Pro/Scripts/BookPro.cs:353)

How can i fix it