If you have a code Z in box 20 it means you have qualifed business income (QBI). If the amount listed on your K-1 schedule is $0, then the code Z should not have been entered. So, remove the code Z. You can do this by scrolling to the top of the column where the codes are and selecting the top row that is blank. Also, you may want to review the statements attached to the K-1 schedule to see if the QBI amount is listed elsewhere, if so you can enter the amount in place of the $0 amount listed in TurboTax on line 20, code Z.