How to change posting FWBS/FWZE to Customer Account

Currently, dividend received was posted directly to FICO using TCODE FWZE.

The entry is:

Debit: Bank

Credit: Revenue - Dividend Received

We are about to do some changes which is, we need to post dividend to the customer and proceed with the clearing (F-28) in which the entry should be:

TCODE: FWZE,

Debit: Customer

Kredit: Revenue - Dividend Received

TCODE: F-28,

Debit: Bank

Kredit: Customer

We have change the configuration in posting specs but the error message "Internal error : Payer/payee has initial value" given when we try to post. What else (configuration) should be done?