diff --git a/CHANGELOG.md b/CHANGELOG.md
index 630c0ef..114016a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 Changelog
 =========
 
+### v 1.3.7
+- Backported function to mid release 2020.3 and 2021.1 SaveAssetIfDirty removed.
+- GUIDFromAssetPath Unity 2019 fix for built-in pipeline.
+
 ### v 1.3.6
 - Runtime components Build fix.
 
diff --git a/Editor/AnimRetargetGUI.cs b/Editor/AnimRetargetGUI.cs
index 5736e7c..9a05d5e 100644
--- a/Editor/AnimRetargetGUI.cs
+++ b/Editor/AnimRetargetGUI.cs
@@ -57,9 +57,7 @@ public static class AnimRetargetGUI
         private static Vector3 animatorPosition;
         private static Quaternion animatorRotation;
 
-
-        // Function variables
-        const string emptyGuid = "00000000000000000000000000000000";
+        // Function variables        
         public const string ANIM_FOLDER_NAME = "Animations";
         public const string RETARGET_FOLDER_NAME = "Retargeted";
         public const string RETARGET_SOURCE_PREFIX = "Imported";
@@ -1252,13 +1250,13 @@ static string GenerateClipAssetPath(AnimationClip originalClip, GameObject fbxAs
 
             if (!overwrite)
             {
-                if (!AssetDatabase.GUIDFromAssetPath(assetPath).ToString().Equals(emptyGuid))
+                if (!Util.AssetPathIsEmpty(assetPath))
                 {
                     for (int i = 0; i < 999; i++)
                     {
                         string extension = string.Format("{0:000}", i);
                         assetPath = Path.Combine(animFolder, animName + "_" + extension + ".anim");
-                        if (AssetDatabase.GUIDFromAssetPath(assetPath).ToString().Equals(emptyGuid)) break;
+                        if (Util.AssetPathIsEmpty(assetPath)) break;
                     }
                 }
             }
diff --git a/Editor/Pipeline.cs b/Editor/Pipeline.cs
index 1362096..c54d8f9 100644
--- a/Editor/Pipeline.cs
+++ b/Editor/Pipeline.cs
@@ -40,7 +40,7 @@ public enum MaterialQuality { None, Default, High, Baked }
 
     public static class Pipeline
     {
-        public const string VERSION = "1.3.6";
+        public const string VERSION = "1.3.7";
 
 #if HDRP_10_5_0_OR_NEWER
         // version
diff --git a/Editor/QuickAnimProcess.cs b/Editor/QuickAnimProcess.cs
index eaaddf9..b6b3fc3 100644
--- a/Editor/QuickAnimProcess.cs
+++ b/Editor/QuickAnimProcess.cs
@@ -88,7 +88,6 @@ public static bool ATValidateInitAssetProcessingForce()
         return IsModel(Selection.activeObject);
     }
 
-    private static string emptyGuid = "00000000000000000000000000000000";
     private static string[] modelFileExtensions = new string[] { ".fbx", ".blend", ".dae", ".obj" };
 
     public static bool IsModel(Object o)
@@ -224,16 +223,14 @@ private static void WriteAnimationClip(Object o, AnimationClip animationClip)
         string animName = SanitizeName(o.name + " - " + animationClip.name);
         string fullOutputPath = workingDirectory + "/" + animName + ".anim";
 
-        if (!AssetDatabase.GUIDFromAssetPath(fullOutputPath).ToString().Equals(emptyGuid))
+        
+        if (AssetPathIsEmpty(fullOutputPath))
         {
             for (int i = 0; i < 999; i++)
             {
                 string extension = string.Format("{0:000}", i);
                 fullOutputPath = workingDirectory + "/" + animName + "." + extension + ".anim";
-                if (AssetDatabase.GUIDFromAssetPath(fullOutputPath).ToString().Equals(emptyGuid))
-                {
-                    break;
-                }
+                if (AssetPathIsEmpty(fullOutputPath)) break;
             }
         }
         Debug.Log("Writing Asset: " + fullOutputPath);
@@ -247,4 +244,11 @@ private static string SanitizeName(string inputName)
         Regex r = new Regex(string.Format("[{0}]", Regex.Escape(invalid)));
         return r.Replace(inputName, " - ");
     }
+
+    public static bool AssetPathIsEmpty(string assetPath)
+    {
+        const string emptyGuid = "00000000000000000000000000000000";
+
+        return AssetDatabase.AssetPathToGUID(assetPath).Equals(emptyGuid);
+    }
 }
diff --git a/Editor/Util.cs b/Editor/Util.cs
index 8f6b4bc..5f92c80 100644
--- a/Editor/Util.cs
+++ b/Editor/Util.cs
@@ -20,6 +20,7 @@
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEditor;
+using Object = UnityEngine.Object;
 
 namespace Reallusion.Import
 {
@@ -895,6 +896,13 @@ public static void FindSceneObjects(Transform root, string search, List<GameObje
             }
         }
 
+        public static bool AssetPathIsEmpty(string assetPath)
+        {
+            const string emptyGuid = "00000000000000000000000000000000";
+
+            return AssetDatabase.AssetPathToGUID(assetPath).Equals(emptyGuid);
+        }
+
         public static void LogInfo(string message)
         {
             if (LOG_LEVEL >= 2)
diff --git a/Runtime/PhysicsSettingsStore.cs b/Runtime/PhysicsSettingsStore.cs
index ba3f37a..3b98a0f 100644
--- a/Runtime/PhysicsSettingsStore.cs
+++ b/Runtime/PhysicsSettingsStore.cs
@@ -97,7 +97,11 @@ public static PhysicsSettingsStore SaveColliderSettings(ColliderManager collider
 			{
 				settings.colliderSettings = workingSettings;
 				EditorUtility.SetDirty(settings);
+#if UNITY_2021_2_OR_NEWER
 				AssetDatabase.SaveAssetIfDirty(AssetDatabase.GUIDFromAssetPath(AssetDatabase.GetAssetPath(settings)));
+#else
+				AssetDatabase.SaveAssets();
+#endif
 
 				Debug.Log("Collider settings stored.");
 
@@ -161,8 +165,14 @@ public static PhysicsSettingsStore SaveClothSettings(WeightMapper weightMapper)
 						settings.clothSettings.Add(s);
 					}
 				}
+
 				EditorUtility.SetDirty(settings);
+#if UNITY_2021_2_OR_NEWER
 				AssetDatabase.SaveAssetIfDirty(AssetDatabase.GUIDFromAssetPath(AssetDatabase.GetAssetPath(settings)));
+#else
+				AssetDatabase.SaveAssets();
+#endif
+
 
 				Debug.Log("Cloth physics settings stored.");
 
@@ -252,7 +262,7 @@ private static bool TryGetSavedIndex(List<PhysicsSettings> savedClothSettings, P
 				return true;
 
 			return false;
-		}
+		}		
 #endif
-	}
+			}
 }
diff --git a/package.json b/package.json
index b432200..ce69d63 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "com.soupday.cc3_unity_tools",
-  "version": "1.3.6",
+  "version": "1.3.7",
   "displayName": "CC/iC Unity Tools HDRP",
   "description": "Unity importer for Character Creator 3 & 4 and iClone 7 and 8.",
   "unity": "2020.3",