Just reporting a Bug/Glitch/Hand-shake issue that is tied to the new RTX 50XX Series.
Sometimes when you start a movie with the new RTX 5090, you just get a blackscreen in MPC-HE Video Player with the Audio still playing.
In Event Viewer, Error logs Event 153 : "The description for Event ID 153 from source nvlddmkm cannot be found"

Easy solved by just restarting the video. (Once or multiple times)
Otherwise, it works all fine. If it starts playing, no black screens or problems occur during video playback.
When using another renderer or video player, it doesn’t occur—only with the RTX HDR Mod from GitHub.
This didn't happen with the RTX 40XX Series.