Oxygen 4.0.4 is a minor releases that focuses on bug fixes and improvements. Below is a list of changes present in Oxygen 4.0.4:
Oxygen 4.0.4 is available as an in-place update via the Plugins page in the WordPress admin panel. You can also manually download it via the customer portal.
Please be sure to resign your shortcodes and regenerate your CSS cache after updating if coming from an Oxygen version prior to Oxygen 4.0.