Since the amazing release of Minecraft 1.8, CraftBukkit has been down - there have been some updates which support minecraft 1.8 but is unstable at this time. We recommend not to install this plugin until we complete our tests on their latest patch.
If you would like to install it anyway, you can manualy copy it to your server via FTP and rename the craftbukkit's jar file to minecraft_server.jar.
We will put out a sample update later today. Hang in there!
