| Problem | Likely Cause | Solution | |---------|--------------|----------| | Video plays, no sound | MKV contains DTS or AC3 codec that laptop lacks | Use VLC (has built-in decoders) or convert to AAC audio | | Subtitles don’t show | MKV has soft subs, player not configured | In VLC: Subtitle → Sub Track → Select English | | Video is choppy/slow | Laptop too weak for 4K/HEVC | Convert to H.264 (720p) using HandBrake | | MKV file won’t copy to USB | USB formatted as FAT32 (4GB limit) | Reformat USB to exFAT or NTFS (loses data – backup first!) | | Error: “Can’t play this file” on Windows | Using Movies & TV app | Switch to VLC or MPV |