Order contains a value without a quantity

What causes this issue?

The system found that the order contains an item with an order value in
document currency, but which does not have a corresponding quantity.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check the item in the order.
Do you want to <DS:TRAN.CO03>Display order</>?

Error message extract from SAP system. Copyright SAP SE.