Bug fixes and general performance improvements.
You cannot extract this file by itself. You must have all preceding parts ( part1 , part2 , part3 ) and any subsequent parts in the same folder. Watch.Dogs.2.MULTi16.Update.v1.17.part4.rar
It looks like you’re dealing with a specific multi-part archive for a update. Based on the file naming convention, this is part of the v1.17 Title Update , which focuses on bug fixes and technical stability. Update Overview: Watch Dogs 2 v1.17 Bug fixes and general performance improvements