I got stuck at this step for like an hour, eventually the 1099 B worksheet loaded and it was asking to verify "Cost Basis/Adjustment" but with over 400 transactions I had absolutely no idea which transaction it was referring to and I wasn't about to sift through them one by one. So I went back and deleted the 1099 import altogether and input it myself - instead of inputting each transaction individually you can just enter the totals i.e. short term covered/long-term covered proceeds and cost and then upload the 1099 as an attachment. Thank goodness for this option otherwise I would've thrown my computer out the window.
