Why did I get the message "The model of the update file is incompatible with the system model"?

Why did I get the message "The model of the update file is incompatible with the system model"?

Details

DSM update files are not universal across all product models. To perform a manual update, refer to this article. Make sure to download the compatible installation file for your model. For more articles about DSM updates, refer to this index article.