How To Fix VF812 - Total quantity of item &1 has already been credited.

SAP Error Message - Details

• Message type: E = Error

• Message class: VF - Billing

• Message number: 812

• Message text: Total quantity of item &1 has already been credited.

What causes this issue?

Follow-on documents have been created for the document item.
The total quantity of the invoice item has already been credited.

System Response

The new quantity determination results in a negative quantity.
There is no quantity to be displayed.

How to fix this error?

Check whether you want to create a follow-on document for this document
item.
If so, please enter a quantity manually.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.