Receiving an error when doing a transfer in spreadsheet (TAX BOOK)

I am working with the tax team on loading transfers in mass via spreadsheet. I am able to do it within the Corporate book, but for some reason I cannot get it to work within the Tax book. This is under the same user with the same roles. Is there a reason why I am seeing the error below? Any pointers would help. I can manually do transfers one by one, but unable to via spreadsheet.

java.lang.NullPointerException