You plan to use structured data files (SDFs) to update details of a large campaign you're working on. You try to upload everything into Display & Video 360 but get an error. What setting is likely causing that error?

Display & Video 360 (DV360) SDFs are designed for specific entity types. You cannot combine different entity types, such as line items and insertion orders, within a single SDF file. Each file must contain rows pertaining to only one entity type. An SDF with 100 line items is acceptable, as there's no inherent limit preventing a large number of line items in a single file, only practical considerations for manageability. Modifying inventory sources via SDFs is a valid use case. An SDF can also contain both editing and removing operations for the same entity type (e.g., line items), as long as the operations are clearly defined for each row.