[Modify] Edit it

websocket-sharp/WebSocket.cs

@@ -2748,7 +2748,7 @@ namespace WebSocketSharp
     /// <paramref name="data"/> is <see langword="null"/>.
     /// </exception>
     /// <exception cref="ArgumentException">
-    /// <paramref name="data"/> cannot be UTF8 encoded.
+    /// <paramref name="data"/> could not be UTF8 encoded.
     /// </exception>
     public void Send (string data)
     {