Export Render Textures from Unity (Fixed)

using UnityEngine;
using UnityEditor;

namespace CodingJar
{
    /**
     * This class adds a menu item which allows you to save out a render texture to a PNG for proper inspection.
     * It needs to go in an Editor/ folder.
     */
    public static class RenderTextureExporter
    {
        [MenuItem("Assets/Coding Jar/Save Render Texture", true)]
        static bool ValidateSaveRenderTexture()
        {
            RenderTexture rt = Selection.activeObject as RenderTexture;
            return ( rt != null );
        }

        [MenuItem("Assets/Coding Jar/Save Render Texture")]
        static void SaveRenderTexture()
        {
            RenderTexture rt = Selection.activeObject as RenderTexture;
            if ( rt == null )
            {
                EditorUtility.DisplayDialog( "Error", "You need to select a Render Texture", "OK" );
                return;
            }

            string fileName = EditorUtility.SaveFilePanel( "Save As", "Assets/", Selection.activeObject.name, "png" );
            if ( !string.IsNullOrEmpty(fileName) )
            {
                var oldRT = RenderTexture.active;
                RenderTexture.active = rt;

                Texture2D newTexture = new Texture2D( rt.width, rt.height, TextureFormat.ARGB32, false );

                // Write out the results...
                newTexture.ReadPixels( new Rect(0.0f, 0.0f, rt.width, rt.height), 0, 0, false );
                newTexture.Apply(false, false);
                System.IO.File.WriteAllBytes( fileName, newTexture.EncodeToPNG() );

                RenderTexture.active = oldRT;
            }
        }
    }
}