Error when creating a map from OSM data

[Payzman]

I used this tutorial: http://kartograph.org/docs/kartograph.py/osm.html

cli.py, in render_map()
71: K.generate(cfg, args.output, preview=args.preview, format=format, stylesheet=css) kartograph.py, in generate()
41: parse_options(opts) options.py, in parse_options()
64: parse_bounds(opts) options.py, in parse_bounds()
333: data["layer"] = opts['layers'][0]['id']
list index out of range

Any ideas, what might cause this error?