Matlab nnstart / nftool gives subscripted assignment dimension mismatch error

When I try to use the neural network tool, I get an error.

nnstart (brings up gui) click on Input-output and curve fitting (nftool)... opens the neural fitting app.

Click on next. Load example data set (and it doesn't matter which of the matlab-provided example sets I use).

Hitting next again takes me to 'validation and test data'.

I don't change anything, hit next again, taking me to 'network architecture'.

Attempting to hit 'next' in network architecture gives a gui-error of

Unable to Create Network Subscripted assignment dimension mismatch

It's error-ing in the gui only, no errors are given in the command line, and no debug info is provided.

[Walter Roberson]

At the MATLAB command line give the command

dbstop if caught error

and run through the sequence again. That should stop at the line that actually caused the problem. If you could show which line that is and what the size() are of the items involved, someone might be able to figure something out, perhaps.