The Plugin RPGitems is a broken plugin, by I mean that the give command and 1 other are both not working and they give a "Internal Server Error, This command can't be run" or something like that. Also, just a FYI, I also Installed all dependencies which are NyaaCore, and LanguageUtils
Link:
https://www.spigotmc.org/resources/rpgitems.17549/