Apparently the Arduino team has made some changes to the Arduino NANO and their software. If you are having an issue getting software to upload, try selecting the "Old Bootloader" option. Also make sure you have the Board: Arduino NANO and the currect PORT selected. The easiest way to ensure the correct port is to unplug the USB cable and make note of the current ports listed (if any are displayed). After plugging in the USB cable, with NANO attached to other end, a new port number should be displayed. Make sure this new port number is selected.