These error messages appear when the media player fails to detect the attached screen over RS-232. The cause could be due to the screen being unexpectedly powered off, or it could occur due to an issue with the RS-232 connection, even when the screen is powered on. The player usually continues to playback content even if it is exhibiting an RS-232 error.
To learn more about RS-232 control, refer to the Screen Monitoring article.
If you are not using RS-232 control and wish to clear these error messages, the RS-232 setting can be disabled in the site's Screen Settings assignment by selecting "No panel control".
