tvOS 12.1.1 (build 16K45) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-12-05T18:08:50Z. The update package is 1.18 GB. This is a delta (partial) update that requires 9.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f56aa495b55cc95a8d7927245c7ba3a28acd9662.zip.