In some versions of MATLAB, if a neural network is trained normally with the Training Tool GUI, the training is stopped or cancelled by the user, and then the user tries to train with command-line only output, training stops at epoch 0. I have forwarded the details of this issue to our development team so that they can investigate it further. To correct the behavior, please use one of the following workarounds:
1. Train any neural network through the GUI and allow the training to complete. This can be a simple example such as the one given in the documentation for "feedforwardnet":
After the training has completed, you should be able to train networks with the GUI disabled.
2. Restart MATLAB.