The Data Warehouse tool processes the file and then keeps the processed file on its server so that it can resend if needed. This file is kept for a few days (I think about a week) and then purged. Since you are trying to resend a file which was processed on February 6th, the server doesn't have that file any more and thus the error.
I have set the file to be reprocessed, and once that is done, it should resend the file. Hope that helps!