'recognition finished with errors (Bad value for option "--plugin".'

[ghost]

Game info

VNDB link: https://vndb.org/v16484
Developer: Grand Cross
Release date: 2014-12-30
Original title: マキフェス！
English title (if available): Maki Fes!

Details

I saw people have extracted this game with arc_unpacker before and wanted to try it but no matter what I did I always got:

C:\Users\Alex\Downloads\arc_unpacker-0.11-bin>C:\Users\Alex\Downloads\arc_unpacker-0.11-bin\arc_unpacker.exe C:\Users\Alex\Downloads\arc_unpacker-0.11-bin\MAKIFES_G.WAR --dec=shiina-rio/warc --plugin=maki-fes
[task 0] MAKIFES_G~.WAR: initial recognition...
[task 0] MAKIFES_G~.WAR: guessing decoder among 1 decoders...
[task 0] MAKIFES_G~.WAR: recognized as shiina-rio/warc.
[task 0] MAKIFES_G~.WAR: recognition finished with errors (Bad value for option "--plugin".
[task 0] MAKIFES_G~.WAR:
[task 0] MAKIFES_G~.WAR: Available PLUGIN values:
[task 0] MAKIFES_G~.WAR:
[task 0] MAKIFES_G~.WAR: - 237 Generic ShiinaRio v2.37
[task 0] MAKIFES_G~.WAR: - shojo-mama Shojo Mama
[task 0] MAKIFES_G~.WAR: - majime1 Majime to Sasayakareru Ore wo Osananajimi no Risa ga
[task 0] MAKIFES_G~.WAR: Seiteki na Imi mo Komete Kanraku Shite Iku Hanashi (sic)
[task 0] MAKIFES_G~.WAR: - sorcery-jokers Sorcery Jokers
[task 0] MAKIFES_G~.WAR: - gh-nurse Gohoushi Nurse
[task 0] MAKIFES_G~.WAR: )
Executed 1 tasks in 0.01s (1 problem, 0 saved files)

I think I'm doing this right. I've tried doing it another way around (arc_unpacker.exe [decoder] [plugin] [file]) but that didn't work either and still gave me the error. How can I resolve it? I know it's a valid plugin since I saw this:
370e194

[yenting-chen]

FYI, I solve similar problem by building arc_unpacker.exe from source files (instead of downloading the released version), because the last release is too old and doesn't contain support for the game yet.