No top layer could you help me out?

[CarrotCraft]

THIS IS WHATS HAPPENING HERES THE CODE FOR WORLD-
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class World : MonoBehaviour {

public Transform player;
public Vector3 spawn;

public Material material;
public BlockType[] blocktypes;

Chunk[,] chunks = new Chunk[VoxelData.WorldSizeInChunks, VoxelData.WorldSizeInChunks];
List<ChunkCoord> activeChunks = new List<ChunkCoord>();
ChunkCoord playerLastChunkCoord;

private void Start() {

	GenerateWorld();
	playerLastChunkCoord = GetChunkCoordFromVector3(player.transform.position);

}

private void Update() {

	if (!GetChunkCoordFromVector3(player.transform.position).Equals(playerLastChunkCoord))
		CheckViewDistance();

}

ChunkCoord GetChunkCoordFromVector3 (Vector3 pos) {

	int x = Mathf.FloorToInt(pos.x / VoxelData.ChunkWidth);
	int z = Mathf.FloorToInt(pos.z / VoxelData.ChunkWidth);
	return new ChunkCoord(x, z);

}

private void GenerateWorld () {

	for (int x = VoxelData.WorldSizeInChunks / 2 - VoxelData.ViewDistanceInChunks / 2; x < VoxelData.WorldSizeInChunks / 2 + VoxelData.ViewDistanceInChunks / 2; x++) {
		for (int z = VoxelData.WorldSizeInChunks / 2 - VoxelData.ViewDistanceInChunks / 2; z < VoxelData.WorldSizeInChunks / 2 + VoxelData.ViewDistanceInChunks / 2; z++) {

			CreateChunk(new ChunkCoord(x, z));

		}
	}

	spawn = new Vector3(VoxelData.WorldSizeInBlocks / 2, VoxelData.ChunkHeight + 2, VoxelData.WorldSizeInBlocks / 2);
	player.position = spawn;

}

private void CheckViewDistance () {

	int chunkX = Mathf.FloorToInt(player.position.x / VoxelData.ChunkWidth);
	int chunkZ = Mathf.FloorToInt(player.position.z / VoxelData.ChunkWidth);

	List<ChunkCoord> previouslyActiveChunks = new List<ChunkCoord>(activeChunks);

	for (int x = chunkX - VoxelData.ViewDistanceInChunks / 2; x < chunkX + VoxelData.ViewDistanceInChunks / 2; x++) {
		for (int z = chunkZ - VoxelData.ViewDistanceInChunks / 2; z < chunkZ + VoxelData.ViewDistanceInChunks / 2; z++) {

			// If the chunk is within the world bounds and it has not been created.
			if (IsChunkInWorld(x, z)) {

				ChunkCoord thisChunk = new ChunkCoord(x, z);

				if (chunks[x, z] == null)
					CreateChunk(thisChunk);
				else if (!chunks[x, z].isActive) {
					chunks[x, z].isActive = true;
					activeChunks.Add(thisChunk);
				}
				// Check if this chunk was already in the active chunks list.
				for (int i = 0; i < previouslyActiveChunks.Count; i++) {

					//if (previouslyActiveChunks[i].Equals(new ChunkCoord(x, z)))
					if (previouslyActiveChunks[i].x == x && previouslyActiveChunks[i].z == z)
						previouslyActiveChunks.RemoveAt(i);

				}

			}
		}
	}

	foreach (ChunkCoord coord in previouslyActiveChunks)
		chunks[coord.x, coord.z].isActive = false;

}

bool IsChunkInWorld(int x, int z) {

	if (x > 0 && x < VoxelData.WorldSizeInChunks - 1 && z > 0 && z < VoxelData.WorldSizeInChunks - 1)
		return true;
	else
		return false;

}

private void CreateChunk (ChunkCoord coord) {

	chunks[coord.x, coord.z] = new Chunk(new ChunkCoord(coord.x, coord.z), this);
	activeChunks.Add(new ChunkCoord(coord.x, coord.z));


}

public byte GetVoxel (Vector3 pos) {

	if (pos.x < 0 || pos.x > VoxelData.WorldSizeInBlocks - 1 || pos.y < 0 || pos.y > VoxelData.ChunkHeight - 1 || pos.z < 0 || pos.z > VoxelData.WorldSizeInBlocks - 1)
		return 0;
	if (pos.y < 1)
		return 1;
	else if (pos.y == VoxelData.ChunkHeight - 1)
		return 3;
	else
		return 2;

}

}

public class ChunkCoord {

public int x;
public int z;

public ChunkCoord (int _x, int _z) {

	x = _x;
	z = _z;

}

public bool Equals(ChunkCoord other) {

	if (other == null)
		return false;
	else if (other.x == x && other.z == z)
		return true;
	else
		return false;

}

}

[System.Serializable]
public class BlockType {

public string blockName;
public bool isSolid;

[Header("Texture Values")]
public int backFaceTexture;
public int frontFaceTexture;
public int topFaceTexture;
public int bottomFaceTexture;
public int leftFaceTexture;
public int rightFaceTexture;

// Back, Front, Top, Bottom, Left, Right

public int GetTextureID (int faceIndex) {

	switch (faceIndex) {

	case 0:
		return backFaceTexture;
	case 1:
		return frontFaceTexture;
	case 2:
		return topFaceTexture;
	case 3:
		return bottomFaceTexture;
	case 4:
		return leftFaceTexture;
	case 5:
		return rightFaceTexture;
	default:
		Debug.Log("Error in GetTextureID; invalid face index");
		return 0;


	}

}

}