Thanks for posting. Hopefully we can provide some clarity on the issue you are having. Nuketown 2025 is now free for download Activision Support . There's no need for a code. Please check your download history/list to see if Nuketown 2025 is listed. If not, you will need to download the content before connecting to an online match.
This is not to be confused with Nuketown Zombies. This is available with the Season Pass or one of the Collector's Edition Activision Support . If you have purchased one of the Collector's Edition and are experiencing an issue with the code provided, please contact the retailer form which the purchase was made. If you are experiencing an issue with the Season Pass code, please contact Microsoft or Sony for further assistance with the code.