Hi, For some reason this morning I can't drag files up or down in a finder window in Mac OS Sierra on my 2012 MBP. Before if I dragged a file up towards the top/bottom of the window the window wold scroll up/down so I could place the file in a folder etc that might be at the top/bottom of the window. Now if I drag the file to the top/bottom nothing generally happens. Sometimes it will stutter and move down one row of files and then stop again. What's going on and how can I fix it? Thanks.