diff --git a/Assets/VRM/UniGLTF/Editor/Tests/UniGLTFTests.cs b/Assets/VRM/UniGLTF/Editor/Tests/UniGLTFTests.cs
index b9d5677426..ce5d0ebeea 100644
--- a/Assets/VRM/UniGLTF/Editor/Tests/UniGLTFTests.cs
+++ b/Assets/VRM/UniGLTF/Editor/Tests/UniGLTFTests.cs
@@ -647,25 +647,81 @@ public void SameMeshButDifferentMaterialExport()
                 Assert.AreNotEqual(gltf.nodes[0].mesh, gltf.nodes[1].mesh);
 
                 // import
-                var context = new ImporterContext();
-                context.ParseJson(json, new SimpleStorage(new ArraySegment<byte>(new byte[1024 * 1024])));
-                //Debug.LogFormat("{0}", context.Json);
-                context.Load();
-
-                var importedRed = context.Root.transform.GetChild(0);
-                var importedRedMaterial = importedRed.GetComponent<Renderer>().sharedMaterial;
-                Assert.AreEqual("red", importedRedMaterial.name);
-                Assert.AreEqual(Color.red, importedRedMaterial.color);
+                {
+                    var context = new ImporterContext();
+                    context.ParseJson(json, new SimpleStorage(new ArraySegment<byte>(new byte[1024 * 1024])));
+                    //Debug.LogFormat("{0}", context.Json);
+                    context.Load();
+
+                    var importedRed = context.Root.transform.GetChild(0);
+                    var importedRedMaterial = importedRed.GetComponent<Renderer>().sharedMaterial;
+                    Assert.AreEqual("red", importedRedMaterial.name);
+                    Assert.AreEqual(Color.red, importedRedMaterial.color);
+
+                    var importedBlue = context.Root.transform.GetChild(1);
+                    var importedBlueMaterial = importedBlue.GetComponent<Renderer>().sharedMaterial;
+                    Assert.AreEqual("blue", importedBlueMaterial.name);
+                    Assert.AreEqual(Color.blue, importedBlueMaterial.color);
+                }
 
-                var importedBlue = context.Root.transform.GetChild(1);
-                var importedBlueMaterial = importedBlue.GetComponent<Renderer>().sharedMaterial;
-                Assert.AreEqual("blue", importedBlueMaterial.name);
-                Assert.AreEqual(Color.blue, importedBlueMaterial.color);
+                // import new version
+                {
+                    var context = new ImporterContext
+                    {
+                        UseUniJSONParser = true
+                    };
+                    context.ParseJson(json, new SimpleStorage(new ArraySegment<byte>(new byte[1024 * 1024])));
+                    //Debug.LogFormat("{0}", context.Json);
+                    context.Load();
+
+                    var importedRed = context.Root.transform.GetChild(0);
+                    var importedRedMaterial = importedRed.GetComponent<Renderer>().sharedMaterial;
+                    Assert.AreEqual("red", importedRedMaterial.name);
+                    Assert.AreEqual(Color.red, importedRedMaterial.color);
+
+                    var importedBlue = context.Root.transform.GetChild(1);
+                    var importedBlueMaterial = importedBlue.GetComponent<Renderer>().sharedMaterial;
+                    Assert.AreEqual("blue", importedBlueMaterial.name);
+                    Assert.AreEqual(Color.blue, importedBlueMaterial.color);
+                }
             }
             finally
             {
                 GameObject.DestroyImmediate(go);
             }
         }
+
+        [Serializable]
+        class CantConstruct
+        {
+            public bool Value = true;
+
+            public CantConstruct(bool value)
+            {
+                throw new Exception();
+            }
+        }
+
+        [Serializable]
+        class Dummy
+        {
+            public CantConstruct Value;
+        }
+
+        [Test]
+        public void JsonUtilityTest()
+        {
+            var dummy = JsonUtility.FromJson<Dummy>("{}");
+            Assert.NotNull(dummy.Value);
+            Assert.False(dummy.Value.Value);
+        }
+
+        [Test]
+        public void UniJSONTest()
+        {
+            var dummy = default(Dummy);
+            "{}".ParseAsJson().Deserialize(ref dummy);
+            Assert.Null(dummy.Value);
+        }
     }
 }
diff --git a/Assets/VRM/UniGLTF/Scripts/Format/glTFBuffer.cs b/Assets/VRM/UniGLTF/Scripts/Format/glTFBuffer.cs
index c47975e4f0..14f2cd7adb 100644
--- a/Assets/VRM/UniGLTF/Scripts/Format/glTFBuffer.cs
+++ b/Assets/VRM/UniGLTF/Scripts/Format/glTFBuffer.cs
@@ -24,6 +24,11 @@ public void OpenStorage(IStorage storage)
             */
         }
 
+        public glTFBuffer()
+        {
+
+        }
+
         public glTFBuffer(IBytesBuffer storage)
         {
             Storage = storage;
diff --git a/Assets/VRM/UniGLTF/Scripts/Format/glTFMesh.cs b/Assets/VRM/UniGLTF/Scripts/Format/glTFMesh.cs
index 315041653a..072084d3da 100644
--- a/Assets/VRM/UniGLTF/Scripts/Format/glTFMesh.cs
+++ b/Assets/VRM/UniGLTF/Scripts/Format/glTFMesh.cs
@@ -141,7 +141,7 @@ public class glTFMesh : JsonSerializableBase
         public string name;
 
         [JsonSchema(Required = true, MinItems = 1)]
-        public List<glTFPrimitives> primitives;
+        public List<glTFPrimitives> primitives = new List<glTFPrimitives>();
 
         [JsonSchema(MinItems = 1)]
         public float[] weights;
@@ -150,10 +150,13 @@ public class glTFMesh : JsonSerializableBase
         public object extensions;
         public object extras;
 
+        public glTFMesh()
+        {
+        }
+
         public glTFMesh(string _name)
         {
             name = _name;
-            primitives = new List<glTFPrimitives>();
         }
 
         protected override void SerializeMembers(GLTFJsonFormatter f)
diff --git a/Assets/VRM/UniGLTF/Scripts/IO/ImporterContext.cs b/Assets/VRM/UniGLTF/Scripts/IO/ImporterContext.cs
index 82c78e51ee..096699a06e 100644
--- a/Assets/VRM/UniGLTF/Scripts/IO/ImporterContext.cs
+++ b/Assets/VRM/UniGLTF/Scripts/IO/ImporterContext.cs
@@ -6,6 +6,7 @@
 using System.Text;
 using System.Collections;
 using DepthFirstScheduler;
+using UniJSON;
 #if UNITY_EDITOR
 using UnityEditor;
 #endif
@@ -259,12 +260,21 @@ public void ParseGlb(Byte[] bytes)
                 new SimpleStorage(chunks[1].Bytes));
         }
 
+        public bool UseUniJSONParser;
         public virtual void ParseJson(string json, IStorage storage)
         {
             Json = json;
             Storage = storage;
 
-            GLTF = JsonUtility.FromJson<glTF>(Json);
+            if (UseUniJSONParser)
+            {
+                Json.ParseAsJson().Deserialize(ref GLTF);
+            }
+            else
+            {
+                GLTF = JsonUtility.FromJson<glTF>(Json);
+            }
+
             if (GLTF.asset.version != "2.0")
             {
                 throw new UniGLTFException("unknown gltf version {0}", GLTF.asset.version);
diff --git a/Assets/VRM/UniGLTF/Scripts/IO/MaterialImporter.cs b/Assets/VRM/UniGLTF/Scripts/IO/MaterialImporter.cs
index 8e9cd4b031..8453792ccf 100644
--- a/Assets/VRM/UniGLTF/Scripts/IO/MaterialImporter.cs
+++ b/Assets/VRM/UniGLTF/Scripts/IO/MaterialImporter.cs
@@ -89,10 +89,13 @@ public virtual Material CreateMaterial(int i, glTFMaterial x)
             if (x.extensions != null && x.extensions.KHR_materials_unlit != null)
             {
                 // texture
-                var texture = m_context.GetTexture(x.pbrMetallicRoughness.baseColorTexture.index);
-                if (texture != null)
+                if (x.pbrMetallicRoughness.baseColorTexture != null)
                 {
-                    material.mainTexture = texture.Texture;
+                    var texture = m_context.GetTexture(x.pbrMetallicRoughness.baseColorTexture.index);
+                    if (texture != null)
+                    {
+                        material.mainTexture = texture.Texture;
+                    }
                 }
 
                 // color
@@ -208,7 +211,7 @@ public virtual Material CreateMaterial(int i, glTFMaterial x)
                     material.SetColor("_EmissionColor", new Color(x.emissiveFactor[0], x.emissiveFactor[1], x.emissiveFactor[2]));
                 }
 
-                if (x.emissiveTexture.index != -1)
+                if (x.emissiveTexture != null && x.emissiveTexture.index != -1)
                 {
                     var texture = Context.GetTexture(x.emissiveTexture.index);
                     if (texture != null)