This GROUP BY clause needs to be modified, mine looked like this below when I finally got it to run in the app:

GROUP BY prjtask_prj_id, custinfo.cust_name, prjtask.prjtask_id, addr.addr_city, addr.addr_state, cntct_name, prjtask.prjtask_number, prjtask.prjtask_status, prjtask_username, prjtask.prjtask_owner_username, prjtask_name, prjtask_descrip, prjtask_due_date, prjtask_assigned_date, prjtask_start_date, prjtask_completed_date, prjtask_hours_budget, prjtask_hours_actual, prjtask_exp_budget, prjtask_exp_actual