The error occurs when updating child matrix items.
In the CSV file, enter a separate column for the parent matrix item and another for the child matrix item. The CSV file will look like the following:
| Item Name/Number | Subitem of | Department |
| Child item | Parent item | — |
In the Item Name/Number column, the Parent : Child format should not be used.
The Child Matrix Item Name is entered without the Parent Matrix Item name.
For example, use Basket rather than Containers : Basket.
You can also use the internal ID of the child matrix item.