Type or namespace could not be found

Hello, I am having an issue when trying to run my game. I am currently learning off this tutorial and I have imported the Characters package but when I try and run it is throwing errors in the console.

Assets/Standard Assets/CrossPlatformInput/Scripts/AxisTouchButton.cs(3,19): error CS0234: The type or namespace name `EventSystems' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/AxisTouchButton.cs(7,55): error CS0246: The type or namespace name `IPointerDownHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/AxisTouchButton.cs(7,76): error CS0246: The type or namespace name `IPointerUpHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/Joystick.cs(3,19): error CS0234: The type or namespace name `EventSystems' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/Joystick.cs(7,48): error CS0246: The type or namespace name `IPointerDownHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/Joystick.cs(7,69): error CS0246: The type or namespace name `IPointerUpHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/Joystick.cs(7,88): error CS0246: The type or namespace name `IDragHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/TouchPad.cs(3,19): error CS0234: The type or namespace name `EventSystems' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/TouchPad.cs(4,19): error CS0234: The type or namespace name `UI' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/TouchPad.cs(9,48): error CS0246: The type or namespace name `IPointerDownHandler' could not be found. Are you missing a using directive or an assembly reference?
Assets/Standard Assets/CrossPlatformInput/Scripts/TouchPad.cs(9,69): error CS0246: The type or namespace name `IPointerUpHandler' could not be found. Are you missing a using directive or an assembly reference?
Failed to load package manager
UnityEditor.Modules.ModuleUtils:GetAdditionalReferencesForUserScripts()
UnityEditorInternal.InternalEditorUtility:GetMonoIslands()
UnityEditor.SyncVS:CreateIfDoesntExist()
UnityEditorInternal.LogEntries:RowGotDoubleClicked(Int32)
UnityEditor.DockArea:OnGUI()

I’m using Unity 5.0.1f1 Personal

Necesitas actualizar a Unity 5.3

Must update to unity 5.3