Why does my nntool not work?

I am trying to set up a neural network using the nntool function. As this is a Matlab toolbox, I don't have a code to show you, but my intention is to predict a stock price. I am using the opening prices as input data and the closing prices as target data.

My problem is that every time I try to train my network, I get the following error message:

I already tried to reduce my input data, but the message still appears. Can anyone help me with that???

[Greg Heath]

 [ I N ] = size(input) % = ?

 [ O N ] = size(target) % = ?

[Walter Roberson]

The error message looks familiar. Isn't that the same error message as the case the other day where the user was attempting to assign to "train" and you said that train was reserved?

[Greg Heath]

@Walter Not sure.

%Michaela: Can you run the documentation example?