Problem/Bug Group Manager 2.13.1 isn't working?

I'm making a minecraft server and I want to have ranks. I want to be able to give permissions to certain ranks etc. I installed Group Manager and it just doesn't work. I attempt to give a pre-made group, such as "Moderator" a prefix, and it won't work. I type:

/mangaddv Moderator prefix [Mod]

and it says "Variable prefix:'[Mod]' added to the group Moderator" but then I proceed to type in chat, and no prefixes come up. Any possible solutions?

 

Does prefixes for other groups show up? And make sure you have a chat plugin such as EssentialsChat installed on the server.

 

Prefixes for other groups don't show up. Also, I tried installing EssentialsChat and that didn't seem to help either. I have these essentials plugins installed:

EssentialsGeoIP
EssentialsXMPP
Essentials
EssentialsSpawn
EssentialsProtect
EssentialsAntiBuild
EssentialsGroupManager

I don't know if that will help, but just giving out a bit more info about my problem

 

pvprealm maybe the plugin has a bug in it and all you have to do is wait? I have a problem with group manager myself. But for me it says : All commands are locked due to an error. Check plugins/groupmanager/error.log or console and then try a '/manload'. I have created a thread to that and if you get the same message then this thread can be useful to u later. :http://bukkit.org/threads/groupmanager-all-commands-are-locked-due-to-an-error.374592/