Ensure you have every numbered part of the sequence. If you are missing even one (like DBC.7z.002 ), the extraction will fail. 2. Use a Compatible Tool
The file is a specific part of a larger compressed archive. The .001 suffix indicates it is the first volume of a "split archive" created by the 7-Zip utility . What is DBC.7z.001? DBC.7z.001
CAN DBC File Explained - A Simple Intro [+Editor Playground] Ensure you have every numbered part of the sequence