The serves as the file index. It maps specific playback times to precise byte positions inside the file cluster.
Avidemux is a free, simple video editor designed for quick cutting and filtering. When it opens an MKV file missing an index, it detects the error immediately and prompts you to rebuild it. Download and open Avidemux . Go to File > Open and select your problematic MKV. mkv index free
You do not need to spend $60 on commercial video catalogers. The open-source community has already provided everything you need. The serves as the file index