tvOS 12.1.1 (build 16K45) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-12-05T18:08:56Z. The update package is 818.83 MB. This is a delta (partial) update that requires 11.2.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8957754707a9979f50ec8d69f28bff56c392a9d7.zip.