Don't add non-existent fords, or blindly accept the first suggestion which makes editor warnings go away. It's unlikely that Princess Street would ford the River Medlock, not least because of the ~5 metre difference in height between the road surface and the water. In fact, fords on main roads in city centres in the UK are very unlikely.

Someone else has already fixed this. They shouldn't have needed to. OSM data is used by real people, this isn't just a box-ticking exercise in the tasking manager you've been playing with.