In Forms Mode, click on the k-1 partnership in the left pane to bring it up in the right pane. Scroll down to 17 and just above it is a quickzoom to enter additional foreign info; click on it and it will bring up the additional wks. Scroll down to "Box 16: Foreign transactions." You should see in Row 2, the interest expense highlighted in red. What TT wants is the Income against which the interest expense was used and you would enter it in the cell above. Use the amount in Box 16 code B or C, making sure that the amount is at least equal to the entry in Row 2. That should clear the error.
