Quantity invoiced greater than goods receipt quantity (& &)

What causes this issue?

This message is issued in two cases:
The quantity for which you are entering the invoice is greater than the
difference between the quantity delivered and quantity invoiced to
date.
The invoice is for a service item for which an invoice has already been
posted.
INCLUDE MM_IV_MELDUNGEN OBJECT DOKU ID TX

System Response

The system has established that the product <ZG>(Quantity invoiced -
quantity to be invoiced) * Order price</> is greater than the tolerance
set in the Customizing system for quantity variance.
In the case of purchase-order-based invoice verification, the system
blocks the invoice for payment with the blocking reason "Quantity
variance".

How to fix this error?

Check your entries and make any necessary corrections.
Goods-Receipt based Invoice Verification
Conventional Invoice Verification
The system will not allow the quantity to be posted. For this reason,
you can only post the invoice as a subsequent debit. If you want to do
this, enter the appropriate subsequent debit indicator in the field
<LS>Subsequent debit</>.
Logistics Invoice Verification
If you post the document in spite of the variance, the system makes the
posting and the associated account movements. However, the document
will contain a block indicator, which will not allow it to be paid.
Purchase-Order-based Invoice Verification
If you post the document in spite of the variance, the system will
carry out the posting and the associated account movements. However,
the document will contain a block indicator, which will not allow it to
be paid.
Invoice for a service
When one invoice has been posted for a service item, the item is
considered to be settled. If you receive a second invoice for the item,
you can only enter this as a subsequent debit. Enter the appropriate
subsequent debit indicator in the field <LS>Subsequent debit</>.

Error message extract from SAP system. Copyright SAP SE.