What steps will reproduce the problem?

1. Start the server.

What version of the product are you using?
Vault v1.2.11-b130

Do you have an error log of what happened?

Error occurred while enabling Vault v1.2.11-b130 (Is it up to date?)
java.lang.NoSuchMethodError:
org.bukkit.plugin.PluginDescriptionFile.getAuthors()Ljava/util/ArrayList;
at net.milkbowl.vault.Vault.onEnable(Vault.java:137)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:215)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:336)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:363)
at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:249)
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:231)
at org.bukkit.craftbukkit.CraftServer.(CraftServer.java:183)
at net.minecraft.server.ServerConfigurationManager.(ServerConfigurationManager.java:53)
at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:156)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:420)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:490)

Please provide any additional information below.

I tested Vault v1.2.11-b130 with Craftbukkit R6 (MC: 1.2.2 ) and it will break.

Yup. It work. Thanks a lot.

This method definetely still exists in R6 and was never removed. Generally errors like this are indicative of a bad download, or a dirty server load.

EDIT: apparently bukkit made a breaking change without notifying plugin authors. #136 is just a recompile and should work fine.

We have downloaded the latest version of your pluggin, and with only that pluggin installed, we are having errors.

again build #136 from http://ci.milkbowl.net will work.