Have you selected nano & 328p old bootloader from the tools menu?
I would try, but it doesn't appear to select from 328 or 328oldbootloader.I read many online forums, and I've seen that people mention to select the correct board, processor and port, but I tried now a few computers with different IDE versions and the only choice I have is 328 or 168 (2 choices) - never seen the oldbootloader to be able to select.I would suspect the board is somehow broken, if only it doesn't work on the online creator, but it does with no problems.Finally, I have checked the online creator and there is ATMmega328old, to select from (together with ATMmega168 and ATMmega328). Only on the online creator, never on the installed IDE.Cheers.
You need to install a new version of the board manager; that will give you the option for 'old bootloader'. It's not said that that solves the issue; to our knowledge, this option is required for newer genuine Nanos. The 328 option in the new board manager should work with the newer Nanos, the old bootloader option should allow you to use the older genuine Nanos and the clones.IDE tools -> board -> board managerClick Arduino AVR BoardsSelect version 1.21Click update