"Amazing XXX.mkv.mp4" appears to be a filename that combines two video container formats (.mkv and .mp4). This often happens when a file has been renamed incorrectly or when a user is attempting to convert a video file.
If you are having trouble playing the file because of its unusual naming or codec, these tools are highly recommended for their "all-in-one" codec support: Amazing XXX.mkv.mp4
: A modern, high-performance alternative specifically for macOS users. "Amazing XXX