User is trying to search for an item in the list view of a screen, but it does not show any matching records.
This can happen if you have applied filters on the screen. When searching for records in the screen-level search box, Core only looks for them in the filtered view. That is, Core only searches through the records that match the filter criteria. So you should make sure that the record you are looking for matches the filters you are using. If you are not sure about that, you should remove all the filters (Clear All) before searching.