Use a versatile player like VLC Media Player which supports almost all .mkv formats natively.
Files with double extensions or those found on unverified file-sharing sites often carry significant risks: Use a versatile player like VLC Media Player
Matroska Video ( .mkv ). The double extension ( .mkv.mkv ) is often a result of manual renaming errors or automated tagging by file-sharing software. Content Category: Likely adult entertainment/pornography. Security Warning Use a versatile player like VLC Media Player