: If you receive a "Unexpected end of archive" or "Data error," you are likely missing one of the numbered volumes.
: The software will automatically find the subsequent parts and combine them into the original file. Troubleshooting
: Right-click the .001 file and select Extract Here or Extract to... using 7-Zip or WinRAR . macOS : Use the Unarchiver to open the .001 file.
Do you have the (like .002 or .003) available in your downloads? How to Extract .7z.001 files - Microsoft Q&A