Error Running Query: Query Completed But Returned No Data
This message means that there are no results for the query you tried to run - the data source is properly connected and there are no issues with the connection or service at the moment.
While it's a harmless message, if you have a schedule for a query with no results the scheduler will consider this as an error which will delay the next iteration of this query. If you've scheduled queries with no results, it's better to run them adhoc. But if you still want to schedule them, a bypass would be adding something like
;SELECT 1 at the end.