A file with a extension alongside .7z typically indicates the 15th part of a multi-volume (split) archive created by the 7-Zip software.
Do you have of the archive (starting from .001), or are you missing some files in the sequence? 7Z file extension - PeaZip 015 7z
: Use a tool like 7-Zip or WinRAR and select "Extract". The software will automatically combine all the parts (including .015) to recreate the original file. Alternative Meanings While rare, the .015 extension can also be associated with: A file with a extension alongside