4k Spotlight highlights movies, TV shows, and other programs that are available in 4k UHD (Ultra HD) definition. However, Roku players need to be 4k compatible to deliver UHD content. Roku players that support 4k include the HDR-capable Roku Ultra HD and Premiere+, as well as the Roku Premiere (non HDR-capable).
Roku is working on fixing the problem and says to try loading the 4k Spotlight channel later. You might also try restarting your Roku if opening the channel doesn’t work. Depending on what the developers do to resolve the issue, you may need to download an update.
Read a review of the Roku Ultra with 4k & HDR support, or, view a list of Roku entertainment and news channels.