When running this code, I sometimes get a non-numeric message, not the data that I am expecting. i.e., d = 'HMDS data farm connection is OK:ilhmds' How do I get consistent data? Thanks!

        ibContract = ib.Handle.createContract;
        ibContract.symbol='ES';
        ibContract.secType='FUT';
        ibContract.expiry='201612';
        ibContract.exchange='GLOBEX';
        ibContract.currency='USD';

       startdate = floor(now)-4;
       enddate = now;
       ticktype = '';
       tradehours = true;
       barsize = '15 mins'; 

       d = timeseries(ib,ibContract,startdate,enddate,barsize)