Additional field &1 inconsistent for infotype &2.

What causes this issue?

The additional field &V1& for infotype &V2& exists, but no function
modules can be determined for it.

System Response

How to fix this error?

Please contact your system administrator.

Procedure for System Administrators

A function module is necessary in order to fill the additional field
P&2_AF-&1. Please check if function module "RPAQ_GET_AF_&V2&" exists.
Also check whether there is an alternative function module in table
"T770AF". If so, check instead that this function module exists.

Error message extract from SAP system. Copyright SAP SE.