Might be related to this thread: Patient Counts on Non-Standard Concepts? - #5 by Chris_Knoll
But, you should run the script found here to create the correct achilles_result_concept_count table, and the subsequent script that will populate it with the aggregate concept counts from your achilles execution. The one in Achilles may be out of date, or should probably be removed because the concept counts DRC/RC stuff is basically a WebAPI function.