Form 7203 problem

in the form Line 3B says to enter line 2 from the K-1. 

 

In my case, this is a negative number - it says to enter negative numbers in section three. But, if I leave this blank it comes back with a message that the field can't be blank or 0

 

If  I put in the negative number is says it can't be below 0

 

If I put it in as a positive, it says it conflicts with the negative number is section 3 and if I put in 0, it says field can't be blank.  

 

I can't move past this.  What should go in line 3b if you have a loss?