I have the same problem after updating to the latest TT today. Previous, over a month old TT did not complain on the same data set.
@ErnieS0 Regarding suggestion to re-type manually instead of using import I strongly disagree. I verified that my 1099-B form fully matches printed and transaction history. The negative Gross Sales Price, e.g. 1b Proceeds column, is 100% legitimate for option trading.
