It looks like at least one of the calculations is missing a piece of information (results[entry].workflow[0].calculation_result_ref is undefined), which makes the query fail in query_nomad_archive.ipynb. A simple solution might be to ignore AttributeErrors in the code. We can see how to fix this in the original tutorial.
But maybe we can help you more directly to formulate the query you are interested in. The example query you linked about querying band gap values in NOMAD does seem to work as expected: it returns a list of band gap values and types for the 10 first entries with a band gap between 0-5 eV, ordered by the entry_id. Maybe you could tell us more about what type of information you are interested in?