Not able to train closed-loop for Narnet timeseries.

I am not able to train narnet to make closed-loop.

Error is as follows:

1. * Error using zeros
2. * Requested 1x6166784512 (45.9GB) array exceeds maximum array size preference. Creation of arrays greater than this
3. * limit may take a long time and cause MATLAB to become unresponsive. See array size limit or preference panel for
4. * more information.
5. *
6. * Error in nnMex.perfsJEJJ>iJacobianFunctionForDirection (line 45)
7. * TEMP = zeros(1,ceil(hints.tempSizeFJ/8)*8);
8. *
9. * Error in nnMex.perfsJEJJ (line 8)
10. * [jacobian, TEMP] = iJacobianFunctionForDirection( direction, hints );
11. *
12. * Error in nnCalcLib/perfsJEJJ (line 388)
13. * lib.calcMode.perfsJEJJ(calcNet,lib.calcData,lib.calcHints);
14. *
15. * Error in trainlm>initializeTraining (line 165)
16. * [worker.perf,worker.vperf,worker.tperf,worker.je,worker.jj,worker.gradient] = calcLib.perfsJEJJ(calcNet);
17. *
18. * Error in nnet.train.trainNetwork>trainNetworkInMainThread (line 28)
19. * worker = localFcns.initializeTraining(archNet,calcLib,calcNet,tr);
20. *
21. * Error in nnet.train.trainNetwork (line 16)
22. * [archNet,tr] = trainNetworkInMainThread(archNet,rawData,calcLib,calcNet,tr,feedback,localFcns);
23. *
24. * Error in trainlm>train_network (line 156)
25. * [archNet,tr] = nnet.train.trainNetwork(archNet,rawData,calcLib,calcNet,tr,localfunctions);
26. *
27. * Error in trainlm (line 55)
28. * [out1,out2] = train_network(varargin{2:end});
29. *
30. * Error in network/train (line 369)
31. * [net,tr] = feval(trainFcn,'apply',net,data,calcLib,calcNet,tr);

My Code is as follows:

T=tonndata(sdatat(1:end,1),false,false);
delay=[1:706];
hiddenlayersize=6;
trainFcn='trainlm';
net=narnet(delay,hiddenlayersize,'open',trainFcn);
net.divideFcn='divideblock'; 
net.trainParam.epochs = 3000;
net.divideParam.trainRatio = 70/100;
net.divideParam.valRatio = 15/100;
net.divideParam.testRatio = 15/100;
net.trainParam.min_grad=1e-7;
net.trainParam.max_fail=100;
net.performFcn = 'mse'; 
net.performParam.normalization = 'standard';
net.input.processFcns={'removeconstantrows','mapminmax'}
[Xso,Xio,Aio,Tso]=preparets(net,{},{},T);
rng('default')
net=train(net,Xso,Tso,Xio,Aio);
[Yso,Xfo,Afo]=net(Xso,Xio,Aio);

[netc,Xic,Aic]=closeloop(net,Xfo,Afo);
[Xc,Xic,Aic,Tc] = preparets(netc,{},{},T);
netc=train(netc,Xc,Tc,Xic,Aic);

This step causes the above error.

Please suggest where I am committing mistakes.

Thanks