If "YMBHT.7z" was too large for a single upload, it might be split into pieces like YMBHT.7z.001 , YMBHT.7z.002 , etc. You need all parts to extract it. Does 7z compress better than zip? - Microsoft Community Hub

It uses the LZMA and LZMA2 algorithms to shrink large files or folders significantly.

A single .7z file can theoretically handle sizes up to 16 billion gigabytes .