Message Chat Double problem!

Hallo,
Every time i say something, or other players say something this happends:
http://prntscr.com/9q7t5m
It's only do in one world, In the other worlds its just working :S
This are my plugins:
http://prntscr.com/9q7tih
S.O.S Please help!

 

It might be RealisticChat?

I'm not 100% sure which plugin is causing it, but follow the video below and it'll show you how to troubleshoot your plugins, allowing you to quickly and efficiently figure out which plugin is causing the problem. After you figure out which plugin is causing the problem, you can either deal with it yourself or let us know in this thread and we'll try our best to help!

Video:

 

A lot of times Multiverse plugins may be the problem. Make sure you are using the latest version of both.
1.8 Multiverse can be found at this link : http://ci.onarandombox.com/view/Multiverse/job/Multiverse-Core/