@flamber, thanks for you quick follow-up. It appears to be related to my use of temporary tables in direct SQL queries.
All my queries are written directly in SQL and some create temp tables to use in later statements. With the change to 0.39.1 I also started seeing some failed queries with messages like this: "There is already an object named '#adjEndDates' in the database."
Although it should not be needed, when I explicitly dropped the temp table at top of the query I received the other error ("Select statement did not produce a ResultSet for native query").
So in one case I restructured the query to eliminate use of a temp table and now it runs correctly.