Server error with plugin Monster Apocalypse config

I'm using the Bukkit plugin Monster Apocalypse for MC 1.7.10 running a MC server 1.7.10 all works good un til i change the "Check for the deaggro permission for entity attacks, shooting super arrows, and mega-aggro?:" from "False" to "True" then the console gives me this error: http://pastebin.com/umjALMXW

how do i fix this?