[Please Help!] A few big errors I've been having.

Hello,

So recently I've been having a few errors on my server. Every time someone types in any command, something like this pops up in the console.



This happens for a few of my plugins, not just SimpleUc. Therefore, I suspect it's not a plugin issue, so please don't ask me if I've configured my plugins right :/

Aaand whenever someone types in chat (anything) they get this error, for my chat related plugins, WorldChannels and ChatControl.



So I'm wondering.... is this a bukkit issue? Is it common? Does it have to do with 1.7.2?
I really need help urgently, this is putting my server on standby...

A screeenshot of my plugins:



Does anyone have any ideas for what I can do to fix this? Even ideas.

 

What version of craftbukkit are you using?

 

Not the very latest. I think the one before that. Let me attempt to switch.