The dataset used for downloading EMNIST is no longer working. The url for the download is currently: https://biometrics.nist.gov/EMNIST/matlab.zip However, that url now redirects to https://www.nist.gov/programs-projects/biometrics A fix would require changing the url to a mirror (which I cannot find) or using the "Binary format as the original MNIST dataset" at the bottom of this page: https://www.nist.gov/itl/products-and-services/emnist-dataset