After upgrading to Ver.4.0.1, it is impossible to successfully expand multiple files and folders, contained in the concatenated RAR (ver.5) file format, (ex; .part01.rar to .part99.rar) Each file is recognized as an individual compressed file, and some files saved as fragments in between the compressed files becomes an error, they can not be reproduced. I downgraded the version 3.1.1 using Time Machine, it returned to normal (Probably up to 4.0.0 is normal). My OS version is macOS 10.12.6 Sierra. This is a serious bug, I think.