Matlab 2018 IB TWS Sending Market Order Failure : cannot find method 'placeOrderEx' for class 'COM.TWS_TwsCtrl'

Hi guys,

I am trying to send market order to purchase 1 ES contract, using Trading Tool box command, and encountered error message : cannot find method 'placeOrderEx' for class 'COM.TWS_TwsCtrl',

I'm using Matlab 2018a, the code can connect to TWS, any body has seen this before ?

ib = ibtws('',7496);
pause(0.2)

ibContract = ib.Handle.createContract;
ibContract.symbol = 'ES';                   % 'SPXL';
ibContract.secType = 'FUT';                 % 'STK';
ibContract.exchange = 'GLOBEX';             % 'SMART'; 'GLOBEX';   'ECBOT' for YM contract 
ibContract.currency = 'USD';                % 'USD';
ibContract.LastTradeDateOrContractMonth = '201903';

ibMktOrder = ib.Handle.createOrder;
ibMktOrder.action = 'BUY';           % 'BUY';
ibMktOrder.totalQuantity = 1;        % 100;
ibMktOrder.orderType = 'MKT';        % 'MKT' or 'LMT'

%%% Send Order
id = orderid(ib);
result_send_order = createOrder(ib,ibContract,ibMktOrder,id);

Best regards

Terry