@ultracreeper I had this problem too, when creating the XE a couple of days ago. You have already created your crew, but it does not show up that you have, and instead sends an error code, I know it is not very clear.

Right, make sure you have £100 to verify your crew. This makes it permanent and allows you access to all the crew commands. To do this, type /verify . If it does not tell you that your crew has been verified, or if it does not accept the money, relog. It took me a few attempts to get it working.

If this still does not work, talk to MCShovel as I believe he is the one who coded it. There is also a forum that outlines all the new features here: http://piratemc.com/topic/crew-update/