The synchronous OperationContract method '{0}' in type '{1}' was matched with the asynchronous OperationContract methods ...

The synchronous OperationContract method '{0}' in type '{1}' was matched with the asynchronous OperationContract methods '{2}' and '{3}' because they have the same operation name '{4}'. When a synchronous OperationContract method is matched to a pair of asynchronous OperationContract methods, any additional attributes must be declared on the synchronous OperationContract method. In this case, the asynchronous OperationContract method '{2}' has one or more attributes of type '{5}'. To fix it, remove the '{5}' attribute or attributes from method '{2}'. Alternatively, changing the name of one of the methods will prevent matching.