: Try redownloading the file. If it’s a multi-part archive (e.g., ss_1398.7z.001 ), ensure you have all parts in the same folder before extracting.
You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. ss_1398.7z
You may see large .img or .db files. These are usually meant for restoration, not manual editing. : Try redownloading the file