In 2012 I refi'd a rental property and TT amortized the fees. I sold the property in 2015, Entering 0 on L 21 of the Asset Wks gives an error. How do I deduct the costs?

In 2012 I refinanced a residential rental property and TT amortized the fees.  The entry appears on the Form 4562 Depreciation and Amortization Report as an amortization.  I sold the property in 2015, but TT is not allowing me to dispose of the amortized fees and realize the loss.  Entering $0 on line 21 of the Asset Wks generates an error.  How do I dispose of this amortized expenditure and deduct the remaining costs?