Vaults Plugin for Server

[Ted]

So I recently purchased Imperial Plugins Vaults2Plugin and I installed it how I did every other one of my Imperial Plugins and setup perms, but when a play in game does /vault or anything to do with the plugin, the server crashes. I don't know if there's a better Vaults plugin out there but I see servers with it all the time so if anyone knows that'd be great. Thanks!