Review process complaining about Form 1116 lines that cannot be equal to 0

Hello Community, I have filled in two 1116s to report the different types of Foreign Tax Credit I want to claim. TurboTax is in the Review phase and is raising warnings about certain lines of Form 1116 which the program says cannot be less than or equal to zero. One of these lines in particular is Line 4b3c, so Interest Expense - Deductible other interest - Adjusted basis for total passive activity assets. I have not reported any info whatsoever on Interest Expense and do not have anything to report so I don't understand why I'm getting an error or what to enter in the line to avoid the message and be able to file.