When creating a custom report, be sure to include all the tables (and associated tables) that a user might filter on. If all the necessary tables are not included, you will receive an error when trying to run a report on the "current filter." Although you do not have to use any field from the associated tables, you do need to have them properly linked in the “Database Expert” or “Linking Expert” in Crystal Reports. Use the corresponding Lucity standard reports as a template for linking tables in your custom reports.