diff --git a/Scripts/NodeDataCache.cs b/Scripts/NodeDataCache.cs
index f865ab2..d1bc756 100644
--- a/Scripts/NodeDataCache.cs
+++ b/Scripts/NodeDataCache.cs
@@ -226,7 +226,7 @@ namespace XNode {
                 this.Clear();
 
                 if (keys.Count != values.Count)
-                    throw new System.Exception(string.Format("there are {0} keys and {1} values after deserialization. Make sure that both key and value types are serializable."));
+                    throw new System.Exception(string.Format("there are {0} keys and {1} values after deserialization. Make sure that both key and value types are serializable.", keys.Count, values.Count));
 
                 for (int i = 0; i < keys.Count; i++)
                     this.Add(keys[i], values[i]);