If you prefer using the native Windows "Movies & TV" app, you might see an error stating "Codec missing."

Most "NF WEB-DL" (Netflix Web Download) files use the video codec and E-AC3 (Dolby Digital Plus) audio. Standard players like Windows Media Player often lack the codecs to decode these.

Download VLC Media Player or MPC-HC . These players come with built-in libraries that can handle almost any MKV container. 2. Install HEVC Video Extensions