After I updated my iMac to OS x Sierra my iCal, Address Book and iPhoto became question marks. Can somebody help me how to get rid of these question marks icons on my dock. iCal, Address Book and iPhoto are now showing "?". I know they are now replaced by calendar, contact and photos. I can't get rid of it. It's not giving me option to delete, I even tried to drag it to trash but it keep coming back. I also deleted dock.plist at preferences and still coming back. I went to terminal and followed some command on how to reset the dock and still the same. It's so annoying. Any help would greatly appreciated. Thanks in advance!