Download all parts and make sure they are in the same directory. Part of the download failed or was corrupted. Delete the corrupted part and download it again. "Password required" The creator locked the archive to protect the contents.

Ensure you have downloaded all corresponding pieces of the archive. For example: SPECIAL1205_PACK1.part1.rar SPECIAL1205_PACK1.part2.rar SPECIAL1205_PACK1.part3.rar (if applicable)

Software cannot read a split file if it is missing the beginning or the end.

Go back to the website or source where you got the links to find the password.