FV60 BDC: "Field INVFO-ZFBDT. does not exist in the screen SAPMF05A 1100"

Hello,

I am using BDC to allow users to input invoice/credit memos into SAP through FV60. So far, I have the program working for submitting invoices; however, when it comes to credit memos, I get an error message saying "Specify payment period baseline date".

I've decided to try and record what I've done in FV60 using T-Code SHDB, and tried incorporating the recorded fields into my program; however, I receive the error message stated in the title of this question.

Please help, thanks.

Phillip