diff --git a/bukkit/src/main/java/io/github/gonalez/znpcs/cache/CacheRegistry.java b/bukkit/src/main/java/io/github/gonalez/znpcs/cache/CacheRegistry.java
index d0847ec..8e829a3 100644
--- a/bukkit/src/main/java/io/github/gonalez/znpcs/cache/CacheRegistry.java
+++ b/bukkit/src/main/java/io/github/gonalez/znpcs/cache/CacheRegistry.java
@@ -174,7 +174,7 @@ public final class CacheRegistry {
 
       .withCategory(CacheCategory.ENTITY)
       .withAdditionalData("monster.warden")
-      .withClassName("EntityWarden"))).load();
+      .withClassName("Warden"))).load();
 
   public static final Class<?> ENTITY_BEE_CLASS = (new TypeCache.BaseCache.ClazzLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
 
@@ -591,6 +591,85 @@ public final class CacheRegistry {
       .withCategory(CacheCategory.ENTITY)
       .withClassName(ENTITY_HUMAN_CLASS)
       .withExpectResult(GameProfile.class));
+
+  public static final String PLAYER_MODEL_PARTS_BIN_NAME;
+  static {
+    switch (Utils.getBukkitPackage()){
+      case "v1_15R1":
+      case "v1_15_R1":
+      case "v1_15R2":
+      case "v1_15_R2":
+      case "v1_16R1":
+      case "v1_16_R1":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bq";
+        break;
+      case "v1_16R2":
+      case "v1_16_R2":
+      case "v1_16R3":
+      case "v1_16_R3":
+      case "v1_16R4":
+      case "v1_16_R4":
+      case "v1_16R5":
+      case "v1_16_R5":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bi";
+        break;
+      case "v1_17R1":
+      case "v1_17_R1":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bP";
+        break;
+      case "v1_18R1":
+      case "v1_18_R1":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bQ";
+        break;
+      case "v1_18R2":
+      case "v1_18_R2":
+        //noinspection DuplicateBranchesInSwitch
+        PLAYER_MODEL_PARTS_BIN_NAME = "bP";
+        break;
+      case "v1_19R1":
+      case "v1_19_R1":
+      case "v1_19R2":
+      case "v1_19_R2":
+      case "v1_19R3":
+      case "v1_19_R3":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bO";
+        break;
+      case "v1_19R4":
+      case "v1_19_R4":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bJ";
+        break;
+      case "v1_20R1":
+      case "v1_20_R1":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bL";
+        break;
+      case "v1_20R2":
+      case "v1_20_R2":
+      case "v1_20R3":
+      case "v1_20_R3":
+        PLAYER_MODEL_PARTS_BIN_NAME = "bM";
+        break;
+      default:
+        PLAYER_MODEL_PARTS_BIN_NAME = "PLAYER_MODEL_PARTS";
+        break;
+    }
+    if (PLAYER_MODEL_PARTS_BIN_NAME != null){
+      GET_PLAYER_MODEL_PARTS = new TypeCache.BaseCache.FieldLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
+  
+              .withCategory(CacheCategory.ENTITY)
+              .withFieldName(PLAYER_MODEL_PARTS_BIN_NAME)
+              .withClassName(ENTITY_HUMAN_CLASS));
+    } else {
+      GET_PLAYER_MODEL_PARTS = null;
+    }
+  }
+  public static final TypeCache.BaseCache<Field> GET_PLAYER_MODEL_PARTS;
+  public static final TypeCache.BaseCache<Method> GET_TRACKED_DATA_ID = new TypeCache.BaseCache.MethodLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
+
+          .withCategory(CacheCategory.SYNCHER)
+          .withClassName(DATA_WATCHER_OBJECT)
+          .withMethodName("getId")
+          .withMethodName("a")
+          .withExpectResult(int.class));
   
   public static final TypeCache.BaseCache<Method> GET_ENTITY_ID = new TypeCache.BaseCache.MethodLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
       
@@ -753,14 +832,14 @@ public final class CacheRegistry {
   public static final TypeCache.BaseCache<Method> GET_DATAWATCHER_B_LIST =
       new TypeCache.BaseCache.MethodLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
       .withCategory(CacheCategory.PACKET)
-          .withMethodName("c")
+      .withMethodName("c")
       .withClassName(DATA_WATCHER_CLASS));
 
   public static final TypeCache.BaseCache<Field> PLAYER_CONNECTION_FIELD = new TypeCache.BaseCache.FieldLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
       
       .withCategory(CacheCategory.SERVER_LEVEL)
       .withClassName(ENTITY_PLAYER_CLASS)
-      .withFieldName((Utils.BUKKIT_VERSION > 16) ? "b" : "playerConnection"));
+      .withFieldName((Utils.BUKKIT_VERSION > 16) ? ((Utils.BUKKIT_VERSION >= 20) ? "c" : "b") : "playerConnection"));
   
   public static final TypeCache.BaseCache<Field> NETWORK_MANAGER_FIELD = new TypeCache.BaseCache.FieldLoader((new TypeCache.CacheBuilder(CachePackage.MINECRAFT_SERVER))
       
diff --git a/bukkit/src/main/java/io/github/gonalez/znpcs/npc/NPCSkin.java b/bukkit/src/main/java/io/github/gonalez/znpcs/npc/NPCSkin.java
index 9730115..c49fab5 100644
--- a/bukkit/src/main/java/io/github/gonalez/znpcs/npc/NPCSkin.java
+++ b/bukkit/src/main/java/io/github/gonalez/znpcs/npc/NPCSkin.java
@@ -1,14 +1,16 @@
 package io.github.gonalez.znpcs.npc;
 
+import io.github.gonalez.znpcs.cache.CacheRegistry;
 import io.github.gonalez.znpcs.skin.SkinFetcherBuilder;
 import io.github.gonalez.znpcs.skin.SkinFetcherResult;
 import io.github.gonalez.znpcs.utility.Utils;
 
+import java.util.Objects;
+import java.util.logging.Level;
+
 public class NPCSkin {
   private static final String[] EMPTY_ARRAY = new String[] { "", "" };
   
-  private static final int LAYER_INDEX = SkinLayerValues.findLayerByVersion();
-  
   private final String texture;
   
   private final String signature;
@@ -29,7 +31,7 @@ public String getSignature() {
   }
   
   public int getLayerIndex() {
-    return LAYER_INDEX;
+    return SkinLayerValues.findLayerByVersion();
   }
   
   public static NPCSkin forValues(String... values) {
@@ -58,6 +60,19 @@ enum SkinLayerValues {
     }
     
     static int findLayerByVersion() {
+      try{
+        if (CacheRegistry.GET_PLAYER_MODEL_PARTS != null){
+          //for static field's null is okay
+          Object playerModelParts = CacheRegistry.GET_PLAYER_MODEL_PARTS.load().get(null);
+          return (int) CacheRegistry.GET_TRACKED_DATA_ID.load().invoke(Objects.requireNonNull(playerModelParts));
+        }else{
+          ((java.util.logging.Logger)org.bukkit.Bukkit.getServer().getLogger()).log(Level.INFO, "CacheRegistry.GET_PLAYER_MODEL_PARTS was null. " + Utils.getBukkitPackage()+ ", " +Utils.BUKKIT_VERSION);
+        }
+      }catch (Throwable throwable){
+        org.bukkit.Bukkit.getServer().getLogger().log(Level.INFO, "Could not get Dynamic Layer Id of PlayerModel entitydata", new RuntimeException(throwable));
+      } //Some error occurred. maybe the field did not exist?
+      org.bukkit.Bukkit.getServer().getLogger().log(Level.INFO, "Falling back to hardcoded values.");
+      
       int value = V8.layerValue;
       for (SkinLayerValues skinLayerValue : values()) {
         if (Utils.BUKKIT_VERSION >= skinLayerValue.minVersion)
diff --git a/gradlew b/gradlew
old mode 100644
new mode 100755