don't show the imported object twice in the inspector, see https://forum.unity.com/threads/scriptedimporter-how-to-hide-imported-object-properties.804012/ for problem description.

Author: pschraut

Editor/Texture2DArrayImporterInspector.cs

@@ -56,6 +56,11 @@ Styles styles
         SerializedProperty m_Textures = null;
         ReorderableList m_TextureList = null;
 
+        public override bool showImportedObject
+        {
+            get { return false; }
+        }
+
         public override void OnEnable()
         {
             base.OnEnable();