You cannot open .part1 successfully unless you have all subsequent parts (e.g., .part2.rar , .part3.rar , etc.) in the same folder.
This could refer to a specific language pack (e.g., English Language Assets) or the name of the creator/group who packaged the file.
If you get a "Checksum Error" or "Unexpected End of Archive," it usually means one of the parts is missing or was corrupted during download. Common Use Cases
To successfully extract the contents, you need to follow these steps: