AR Open Load: "Table: ttARInvoiceLoad Msg: Invoice has been posted. Entry not allowed"

We are still developing and practicing our data load process, and have been working on the AR Open Load.

I did a load (DMT Add New), our accounts found some issues, so I reran the AR Open Load with DMT Delete , which ran without errors. I made my corrections, regenerated the csv and reran with DMT Add New but I am now getting these error messages for all records:
Table: ttARInvoiceLoad Msg: Invoice has been posted. Entry not allowed

Does this sound like a bug? Anyway to work around it? Our plan B is to go back to our “base data” (no transactions) and reapply everything we’ve been working on the last few months, which is a pain but is at least practice and validation of the go-live procedure we are devloping.

Thanks,
Chris

Solved: There was an unwanted “posted” column coming through from my source system. Doh.