Can't open Invector Inventory

Iam using the Invector Shooter Template Package.
The Problem is that i can not open the inventory if i do it will pause the game in editor and show up this message in the console:

NullReferenceException: Object reference not set to an instance of an object
Invector.vItemManager.vSetFirstSelectable.SetSelectable (UnityEngine.GameObject target) (at Assets/Invector-3rdPersonController/ItemManager/Scripts/vSetFirstSelectable.cs:32)
Invector.vItemManager.vSetFirstSelectable+c__Iterator0.MoveNext () (at Assets/Invector-3rdPersonController/ItemManager/Scripts/vSetFirstSelectable.cs:25)
UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) (at C:/buildslave/unity/build/Runtime/Export/Coroutines.cs:17)

Here is the C# Script:
alt text

You’ll need to add EventSystem to your scene, as discussed here: