I'm trying to access a List from another script. It gives me the error in the title. What did I do wrong?
TreeGen.cs
 public GameObject Instree;
 int trees;
 public List<int> TreeCount;
void Start() {
trees = Random.Range(100, 300);
     for (int i = 0; i < trees; i++){
       {
            Instree = Instantiate(tree, position, Quaternion.identity);
            TreeCount.Add(Instree.GetInstanceID());
       }
}
TreeDestroy.cs
TreeGen treeGen;
void Update(){
for (int i = 0; i < treeGen.TreeCount.Count; i++) {
            {
                if (treeGen.Instree.GetInstanceID() != treeGen.TreeCount[i])
                {
                    //something to do
                }
            }
        }
}
Note: I know this shouldn't be in Update(), but I want to know if it even works
