Entering Schedule K-1 Box 20 Code P Information

Hello, 

I have received a K-1 for a long standing investment (in which I have an individual/limited partner/no material participation status), which, for the first time, has a Code P entry in Box 20.  As I understand, this is related to Section 453A(c) Deferred Obligation and I have the partner's share of this obligation which, as per IRS instructions, I think needs to go on Schedule 2, line 8c.  Unfortunately, TurboTax will not let me check the box c and enter anything there. Attempting to do so causes the program to crash. I would appreciate any guidance on how to resolve. Thank you.