Updating my server is fine, but the plugins....

Recently I just updated my server, and got it back up and running. However, there are a lot of issues with-even updated- plugins. For example, multiverse (which I know to be very not-dead), whenever I type /mv (anything) it tells me an internal server error has occurred.
The same hold true for mob disguise, and when I try to use chestshop, it will not let me buy or sell anyting with the existing signs, nor create any new ones of my own. Thanks guys.

 

As for MultiVerse, you need to use a development build. I can grab a link for you when I get home if you want, just PM me.

As for the other plugins, check for permissions errors. I know for a fact that ChestShops works in odd ways with permissions.

 

that would be great, thanks Alvarez. As for my permissions file, it's completely empty, as I haven't quite got my head around it yet. But could that be the issue?