On the FIW, Part V, I filled out the Direct Debit info. I am not allowed to fill in an amount to be debited. How can I fill in an amount to be debited?

Are you sure there is an amount due on your return?  I get the screen below when I am due a refund and try to complete a debit. 

I don't think the Federal Info Worksheet has you enter an amount; you are allowing a debit of the amount due.  To get rid of the red X, try checking the No box for allowing direct deposit of tax refund (assuming you do owe tax versus expect a refund).  I had a similar experience on my state return.

None of the responses solved my problem.  What I ultimately did was check "No" for Direct Deposit and left the box blank for Direct Debit.  That removed the red X.  I was able to complete the return and I filed it without any errors showing.  When I review my return a day later, I saw that the FIW was filled in correctly w/o any red marks.