diff --git a/README.md b/README.md
index 7f27b42c..1e53d2ab 100644
--- a/README.md
+++ b/README.md
@@ -28,10 +28,10 @@ In comparison to other projects, like for instance [TensorFlowSharp](https://www
 
 | TensorFlow                 | tf native1.14 | tf native 1.15 | tf native 2.3 |
 | -------------------------- | ------------- | -------------- | ------------- |
-| tf.net 0.3x, tf.keras 0.2x |               |                | x             |
+| tf.net 0.3x, tf.keras 0.2 |               |                | x             |
 | tf.net 0.2x                |               | x              | x             |
-| tf.net 0.1x                | x             | x              |               |
-| tf.net 0.1x                | x             |                |               |
+| tf.net 0.15                | x             | x              |               |
+| tf.net 0.14                | x             |                |               |
 
 Troubleshooting of running example or installation, please  refer [here](tensorflowlib/README.md).
 
diff --git a/src/TensorFlowNET.Core/Tensors/Tensor.Assign.cs b/src/TensorFlowNET.Core/Tensors/Tensor.Assign.cs
index eaaae613..4312a291 100644
--- a/src/TensorFlowNET.Core/Tensors/Tensor.Assign.cs
+++ b/src/TensorFlowNET.Core/Tensors/Tensor.Assign.cs
@@ -18,7 +18,9 @@ namespace Tensorflow
                 return OriginalVar;
             }
             else
-                throw new RuntimeError("Operation doesn't support.");
+            {
+                throw new RuntimeError($"Operation doesn't support. {this.name} is a constant tensor. Make sure to initiate {this.name} from tf.Variable() and declare {this.name} as ResourceVariable or var.");
+            }
         }
     }
 }