I have a problem with calling on W10m on 10586.494, but it's not the first time that this happened. I experienced it with earlier builds also. I need to make a phone call, and I go to phone app, choose contacts, press letter D, scroll to my friend Diana, and phone app just crashes to recent calls! I try again, and again, and again, same thing happen, I cannot make a phone call until I reset phone. Needless to say that to make a phone call, you need 5 steps (which is all by itself really anoying), and then it crashes! I think that my Lumia 640LTE is going to finish it's life on the floor, with me banging it with a hammer. Then I will buy plain old ''button'' phone, which never ever fails with most basic function that was made for!!!