If you see errors on downloaded reports like the ones listed below, this usually means your report contains more rows than is allowed. Set a row limit of 5k or less and try again.
Possible errors:
Error: Refusing to run query with no limit that Looker cannot stream incrementally. Please choose a smaller limit or remove table calculations.
Error: Refusing to run query with no limit that Looker cannot stream incrementally. Please choose a smaller limit or remove the “window” measure types (such as running_total) from the query.