I'm teaching myself about Mathematica 11.3 Neural Net capabilities, and I can't get a demonstrably previously working example to work. I've been trying for quite a while without success.
In Martin van Almsick's talk at WTC 2017, he gave an example of using a single neuron network and one trained on only one input, extracting an image layer, and then asking the trained net to classify that image layer. The idea instructive, but not necessarily useful. Link to Page with Alsmick's talk and notebook, look on the left column near the bottom, see section of notebook about One Neuron Dream.
I think his example version came from a development version of 11.3, I can't get it to work. I'd be very grateful if someone out there could get this example to work in 11.3.