You can typically resolve this by "remuxing" the file, which rebuilds the index without re-encoding the video (preserving original quality). MKVToolNix (GUI)
: Its "index-free" or modular design is specifically built for future expansion, allowing it to support almost any audio, video, or subtitle codec without becoming outdated Key Technical Features mkv index free
Key tools and techniques
: A powerful tool for quick fixes using the following command: ffmpeg -i input.mkv -c copy output.mkv You can typically resolve this by "remuxing" the