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

The synchronous OperationContract method '{0}' in type '{1}' was matched with the task-based asynchronous OperationContract  method '{2}' because they have the same operation name '{3}'. When a synchronous OperationContract method is matched to a task-based asynchronous OperationContract method, the two OperationContracts must have the same value for the '{4}' property. In this case, the values are different. To fix it, change the '{4} property of one of the OperationContracts to match the other. Alternatively, changing the name of one of the methods will prevent matching.