Empty state-space model error : Neural network matlab

[Remy the cook]

I applied neural network toolbox to create a multilayer feedforward network. The data is a huge csv file which maps to three outputs.

data = load('Train.csv'); 
Input= data(1:31012,1:40);
Output=data(1:31012,41);
%net = newff(minmax(Input),[1000,1000,1000]);
net = feedforwardnet(10,'trainlm');
view(net)
y = net(Input);
perf = perform(net,y,Output)

but this code always gives this - "Empty state-space model."
What am I doing wrong?