NHK Plus videos are copy-protected to prevent recording and downloading. The NHK Plus system also has an anti-screen capture function to prevent screen recording; when recording NHK Plus programmes, sound can be heard but the screen often goes dark and recording is not possible. https://www.leawo.org/jp/tips/nhk%E3%83%97%E3%83%A9%E3%82%B9-1352.html?utm_source=bookmarklayer.com&utm_campaign=1352