Revise some details.

src/TensorFlowNET.Keras/Saving/SavedModel/load.cs

@@ -56,7 +56,8 @@ namespace Tensorflow.Keras.Saving.SavedModel
             }
             else
             {
-                throw new NotImplementedException("Not implemented, please submit an issue to https://github.com/SciSharp/TensorFlow.NET/issues.");
+                throw new NotImplementedException("SavedModel saved prior to TF 2.5 detected when loading Keras model, please" +
+                    " use higher version or submit an issue to https://github.com/SciSharp/TensorFlow.NET/issues. to let us know you need it.");
             }
 
             if (metadata.Nodes is null || metadata.Nodes.Count == 0)

test/TensorFlowNET.Keras.UnitTest/SaveModel/SequentialModelLoad.cs

@@ -59,7 +59,7 @@ public class SequentialModelLoad
     }
 
     [TestMethod]
-    public void Temp()
+    public void ModelWithSelfDefinedModule()
     {
         var model = tf.keras.models.load_model(@"Assets/python_func_model");
         model.summary();