Problem you described must be either Australian localization or modification for you…
My guess is, that you have this custom field “EFT”, which is Boolean (Yes/No), for some reasons there sits “No” in situation, when Navision expects it to be “Yes”.
Not knowing what is it all about, I can only suggest setting it to Yes where needed - can it be done manually or system sets it? Once again - its only guess after reading error message you provided…
This is likely related to Chargelogic add-on, it is a credit card processing add-on. There will not be alot of users here that can answer your question, You are going to need to contact your solution center for this.
We use chargelogic, and have had a similar error from time to time, but it can be many things, something to look at, is the eft entry trying to reference an invoice that has already had the payments applied to it, thus it is not open any longer
line 20000 is the second line in the journal. look at it for clues as to what is wrong.
The GB version has BACS functionality which I assume is similar - it works by exporting the journal lines to a text file and marks the record. You must then post the line. Have a look at the second line and see if it’s on a previous EFT file.