How do I download / install updates to Rock Band 4?
Both consoles should automatically prompt or download the most recent update when trying to access the game while connected to the internet.
Your Xbox One should prompt you to download a title update once you choose to play Rock Band 4. If you decline this prompt, you will continue to be prompted to update anytime you play the game. Please refer to this link for installing and updating Rock Band 4 on Xbox One. If you require further assistance, please contact Xbox Customer Support here.
Your PlayStation 4 should automatically begin downloading any title updates to Rock Band 4 once it is turned on or woken up from Rest Mode. The only time this would not happen is if you have manually turned automatic updates off. Please refer to this link for installing and updating Rock Band 4 on PlayStation 4 (located under "Application Update Files"). If you require further assistance, please contact PlayStation Customer Support here.