Diagnosis
You selected a grouping field. A set with the relevant objects isgenerated for every value of this field from the selected data. However,the template entered for the set names does not contain a percentagesign (%) as a placeholder. As a result, all sets to be generated wouldhave the same name.

Procedure
Use the placeholder % in the set names. This is replaced by the value inthe grouping field when the set is generated.
See also the documentation on the set namefield.