1099-B Worksheet

I imported information from my financial institution including the Form 1099-B Worksheet listing several sales of individual companies and the Capital Gains (Losses) for each transaction.  TurboTax says I need to fill out another 1099-B Worksheet for an "Unknown Financial Institution" for "Cost or Adjusted Basis", "Date Sold", Sales Price", "Date Acquired", "Holding Period", Etc.  I don't know this information.  I don't know why this shows up in the TurboTax program since I assume all of this information is in the download from the financial institution.  I cannot file the return until this is satisfied.  Can I override it or how do I complete it?