Ever since I upgraded to Win 10 Hotmail has exhibited a bug where when I try to attach a file it comes back with 'leave this page' and I could not move forward with the attachment. The workaround was to re-start and that would solve the problem and the attachment would work. I have tried other options such as deleting cache etc and none of them work. The only thing that works is a re-start. Is there a MS solution for this please?