Since this is of a multi-part archive, the most useful "feature" is its role in reconstructive extraction. Here is how to use it:

: Use a tool like WinRAR or 7-Zip to open Part 1 ; the software will automatically pull data from Part 3 to build the final .mkv or .mp4 file.

: You cannot open this file alone. You must have all other parts (e.g., part1.rar , part2.rar ) in the same folder to extract the full video.

: Ensure the file size matches the other parts (except usually the last one) to confirm the download wasn't corrupted.

Do you have all the other downloaded in the same folder?