obi Cloth Version 5.6 error

[onur89]

UnsafeUtilityEx is defined in the Collections package. See:
https://docs.unity3d.com/Packages/com.un...ityEx.html

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.Collections.Generic;
using UnityEngine;
using Unity.Collections;
using Unity.Collections.LowLevel.Unsafe;
using System.Collections;

these are already defined but it doesn't see the UnsafeUtilityEx. should I update some thing on package manager ?