Quantity delivered is zero

What causes this issue?

The quantity delivered for the item displayed is zero.
INCLUDE MM_IV_MELDUNGEN OBJECT DOKU ID TX

System Response

The system will block the invoice item when the document is posted,
depending on how the tolerance key DW is set (quantity variance to GR
quantity = zero).

How to fix this error?

Check the quantity entered. If necessary, enter the quantity as zero,
if the invoice refers to another item.

Error message extract from SAP system. Copyright SAP SE.