Working scripted importer version.

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Controls/ObjectControl.cs

 using System.Reflection;
 using UnityEngine;
 using UnityEngine.Experimental.UIElements;
-using UnityEditor.ShaderGraph;
 using Object = UnityEngine.Object;
 
 namespace UnityEditor.ShaderGraph.Drawing.Controls
             var value = (Object) m_PropertyInfo.GetValue(m_Node, null);
             using (var changeCheckScope = new EditorGUI.ChangeCheckScope())
             {
-                value = EditorGUILayout.MiniThumbnailObjectField(m_Label, value, m_PropertyInfo.PropertyType);
+                //value = EditorGUILayout.MiniThumbnailObjectField(m_Label, value, m_PropertyInfo.PropertyType);
                 if (changeCheckScope.changed)
                 {
                     m_Node.owner.owner.RegisterCompleteObjectUndo("Change " + m_Node.name);

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Inspector/IMGUISlotEditorView.cs

 
             if (slot is Texture2DInputMaterialSlot)
             {
-                var dynslot = slot as Texture2DInputMaterialSlot;
-                dynslot.texture = EditorGUILayout.MiniThumbnailObjectField(new GUIContent("Texture"), dynslot.texture, typeof(Texture), null) as Texture;
+                //var dynslot = slot as Texture2DInputMaterialSlot;
+                //dynslot.texture = EditorGUILayout.MiniThumbnailObjectField(new GUIContent("Texture"), dynslot.texture, typeof(Texture), null) as Texture;
             }
             return EditorGUI.EndChangeCheck();
         }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Inspector/ShaderPropertyView.cs

 
         void TextureField()
         {
-            var fProp = (TextureShaderProperty) property;
-            fProp.value.texture = EditorGUILayout.MiniThumbnailObjectField(new GUIContent("Texture"), fProp.value.texture, typeof(Texture), null) as Texture;
+            //var fProp = (TextureShaderProperty) property;
+            //fProp.value.texture = EditorGUILayout.MiniThumbnailObjectField(new GUIContent("Texture"), fProp.value.texture, typeof(Texture), null) as Texture;
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/MaterialGraphEditWindow.cs

                     return;
                 }
 
-                if (m_GraphObject.graph.GetType() == typeof(ShaderGraph.MaterialGraph))
+                if (m_GraphObject.graph.GetType() == typeof(MaterialGraph))
                     UpdateShaderGraphOnDisk(path);
 
                 if (m_GraphObject.graph.GetType() == typeof(LayeredShaderGraph))
             List<PropertyCollector.TextureInfo> configuredTextures;
             graph.GetShader(Path.GetFileNameWithoutExtension(path), GenerationMode.ForReals, out configuredTextures);
 
-            var shaderImporter = AssetImporter.GetAtPath(path) as ShaderImporter;
+            var shaderImporter = AssetImporter.GetAtPath(path) as ShaderGraphImporter;
-
-            var textureNames = new List<string>();
-            var textures = new List<Texture>();
-            foreach (var textureInfo in configuredTextures.Where(x => x.modifiable))
-            {
-                var texture = EditorUtility.InstanceIDToObject(textureInfo.textureId) as Texture;
-                if (texture == null)
-                    continue;
-                textureNames.Add(textureInfo.name);
-                textures.Add(texture);
-            }
-            shaderImporter.SetDefaultTextures(textureNames.ToArray(), textures.ToArray());
-
-            textureNames.Clear();
-            textures.Clear();
-            foreach (var textureInfo in configuredTextures.Where(x => !x.modifiable))
-            {
-                var texture = EditorUtility.InstanceIDToObject(textureInfo.textureId) as Texture;
-                if (texture == null)
-                    continue;
-                textureNames.Add(textureInfo.name);
-                textures.Add(texture);
-            }
-            shaderImporter.SetNonModifiableTextures(textureNames.ToArray(), textures.ToArray());
+            
             File.WriteAllText(path, EditorJsonUtility.ToJson(graph, true));
             shaderImporter.SaveAndReimport();
             AssetDatabase.ImportAsset(path);

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Importers/ShaderGraphImporter.cs

 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
-[ScriptedImporter(2, "shadergraph")]
+[ScriptedImporter(1, "shadergraph")]
 public class ShaderGraphImporter : ScriptedImporter
 {
     private string errorShader = @"
     Fallback Off
 }";
 
+
+        var oldShader = AssetDatabase.LoadAssetAtPath<Shader>(ctx.assetPath);
+        if (oldShader != null)
+            ShaderUtil.ClearShaderErrors(oldShader);
-        var text = GetShaderText<MaterialGraph>(ctx.assetPath);
+        List<PropertyCollector.TextureInfo> configuredTextures;
+        var text = GetShaderText<MaterialGraph>(ctx.assetPath, out configuredTextures);
+        
+        var shader = ShaderUtil.CreateShaderAsset(text);
+        
+        EditorMaterialUtility.SetShaderDefaults(
+            shader,
+            configuredTextures.Where(x => x.modifiable).Select(x => x.name).ToArray(),
+            configuredTextures.Where(x => x.modifiable).Select(x => EditorUtility.InstanceIDToObject(x.textureId) as Texture).ToArray());
+        EditorMaterialUtility.SetShaderNonModifiableDefaults(
+            shader,
+            configuredTextures.Where(x => !x.modifiable).Select(x => x.name).ToArray(),
+            configuredTextures.Where(x => !x.modifiable).Select(x => EditorUtility.InstanceIDToObject(x.textureId) as Texture).ToArray());
-        var shader = ShaderUtil.CreateShaderAsset(text);
-    private static string GetShaderText<T>(string path) where T : IShaderGraph
+    private static string GetShaderText<T>(string path, out List<PropertyCollector.TextureInfo> configuredTextures) where T : IShaderGraph
     {
         try
         {
 
             var name = Path.GetFileNameWithoutExtension(path);
-
-            List<PropertyCollector.TextureInfo> configuredTextures;
             var shaderString = graph.GetShader(string.Format("graphs/{0}", name), GenerationMode.ForReals, out configuredTextures);
             Debug.Log(shaderString);
             return shaderString;
             // ignored
         }
+        configuredTextures = new List<PropertyCollector.TextureInfo>();
         return null;
     }
 }