ArgumentNullException: Value cannot be null when slicing mesh

I'm using this open source mesh slicer and I started playing around with it a little but when instantiating some objects with this script i get the following error:

 ArgumentNullException: Value cannot be null.
 Parameter name: collection
 System.ThrowHelper.ThrowArgumentNullException (System.ExceptionArgument argument) (at <567df3e0919241ba98db88bec4c6696f>:0)
 System.Collections.Generic.List`1[T].InsertRange (System.Int32 index, System.Collections.Generic.IEnumerable`1[T] collection) (at <567df3e0919241ba98db88bec4c6696f>:0)
 System.Collections.Generic.List`1[T].AddRange (System.Collections.Generic.IEnumerable`1[T] collection) (at <567df3e0919241ba98db88bec4c6696f>:0)
 Shatter.ShatterObject (UnityEngine.GameObject obj, UnityEngine.Material crossSectionMaterial) (at Assets/Scripts/Shatter.cs:25)
 Shatter.RandomShatter () (at Assets/Scripts/Shatter.cs:62)
 Shatter.Start () (at Assets/Scripts/Shatter.cs:16)

If anybody has any advice on how to fix this my code is right here:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using EzySlice;
 
 public class Shatter : MonoBehaviour
 {
     public GameObject objectToShatter;
     public Material crossSectionMaterial;
     public int sliceAmount = 1;
 
     public void Start()
     {
         objectToShatter = gameObject;
         crossSectionMaterial = gameObject.GetComponent<Renderer>().material;
         RandomShatter();
     }
     public List<GameObject> ShatterObject(GameObject obj, Material crossSectionMaterial = null)
     {
         List<GameObject> slices = new List<GameObject>();
         for(int c = 0; c < sliceAmount; c++)
         {
             if(c == 0)
             {
                 slices.AddRange(
                 obj.SliceInstantiate(GetRandomPlane(obj.transform.position, obj.transform.localScale),
                                                                     new TextureRegion(0.0f, 0.0f, 1.0f, 1.0f),
                                                                     crossSectionMaterial)
                 );
             }
             else
             {
                 if(slices.Count > 0)
                 {
                     for (int b = 0; b < slices.Count; b++)
                     {
                         slices.AddRange(
                         slices[b].SliceInstantiate(GetRandomPlane(obj.transform.position, obj.transform.localScale),
                                                         new TextureRegion(0.1f, 0.1f, 1.0f, 1.0f),
                                                         crossSectionMaterial)
                         );
                     }
                 }
             }
         }
         return slices;
     }
 
     public EzySlice.Plane GetRandomPlane(Vector3 positionOffset, Vector3 scaleOffset)
     {
         Vector3 randomPosition = Random.insideUnitSphere;
 
         //randomPosition += positionOffset;
 
         Vector3 randomDirection = Random.insideUnitSphere.normalized;
 
         return new EzySlice.Plane(randomPosition, randomDirection);
     }
 
     public void RandomShatter()
     {
         GameObject[] shatters = ShatterObject(objectToShatter, crossSectionMaterial).ToArray();
 
         if (shatters != null && shatters.Length > 0)
         {
             // add rigidbodies and colliders
             foreach (GameObject shatteredObject in shatters)
             {
                 shatteredObject.AddComponent<MeshCollider>().convex = true;
                 shatteredObject.AddComponent<Rigidbody>().useGravity = false;
                 shatteredObject.AddComponent<ShrinkGone>();
             }
             Destroy(gameObject);
         }
         return;
     }
 }