I am posting a new query about this as the old thread about scales not measuring body fat is marked as 'Answered'. In fact the answer given there DOES NOT WORK, and many people have posted to say so, but have not been replied to by the moderators. Let's see if they will reply to this new query.
My Body+ scale worked fine for several years until about a month ago, then suddenly stopped measuring fat. Nothing changed in my use of (or care of) the scale. I have followed all the advice previously given by Withings (clean scale, damp bare feet, etc), and the scale still won't measure fat. It doesn't even try - just goes immediately to the 'X'. This is true even with very damp feet. I think it is very bad customer relations to stop responding to the many people that have this problem in spite of following all the Withings advice. Please, this question has NOT been satisfactorily answered! Would whoever is moderating this forum PLEASE respond with a better answer - the previous suggestions do not work.