Please excuse me if this has already been addressed, I tried searching but didn't see anything about this. When in finder I may highlight a file, press cmmd+C or use the edit menu to copy a file, and then attempt to paste it somewhere using cmmd+V or edit menu. The file seems to be copying, there is a status bar if the file is large, but upon completion the file's name disappears from the folder to which I am copying it. I asked my friends who have upgraded and they haven't experienced this. I have checked for updates, and tried copying various file types. I can drag files to a new location, but sometimes I want to duplicate them (especially photos).