I have the same issue: everything was playing fine until a few weeks ago and no I get black screen on direct stream, nothing happens when trying to play a video.
When activating the logs, it hangs on “buffering” before throwing an error message: “ERROR [Unhandled Rejection]: Unknown error Error: Unknown error at getErrorObjectLocalStore (:1:5960) at callback (:1:9397) at :1:21004 at c (https://app.plex.tv/tv-tizen/main.js:2:4309)”
I could not find any meaningful information in the server logs.