Reporting Form 1099-B Box 1e (Cost or other basis) when it's not reported by the brokerage firm

One of my Forms 1099-B, has the word "Missing" printed in box 1e (Cost or other basis).  TurboTax requires an entry in this box 1e to proceed.  You can't leave it blank, nor will it except accept alpha character to input "Missing" as it appears on the 1099-B.

 

Although, there's no amount in the box, do I just enter 0.00 to proceed to the next screen?

 

Also, the 1099-B was part of a corporate action (merger).  While the basis is not reported (or missing), I know the basis.  Is it best to just enter 0.00 in TurboTax 1099-B, then report the basis on Form 8949.

 

Or, can I report the known basis in TurboTax even though it's not report on the actual 1099-B from the brokerage firm?  If I report the missing basis in TurboTax's 1099-B section, then it's not going to match the brokerage's info they submitted to the IRA.  Will this mismatch cause an issue whey filing?