Error

[20:02:15 WARN]: org.apache.commons.lang.UnhandledException: Plugin PlayerInvent
oryLogger v0.0.1e generated an exception while executing task 14
        at org.bukkit.craftbukkit.v1_7_R2.scheduler.CraftAsyncTask.run(CraftAsyn
cTask.java:56)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoSuchMethodError: net.milkbowl.vault.economy.Economy.getBa
lance(Lorg/bukkit/OfflinePlayer;)D
        at net.wtako.PlayerInventoryLogger.Methods.PIL$1.run(PIL.java:65)
        at net.wtako.PlayerInventoryLogger.Methods.PIL.logPlayer(PIL.java:79)
        at net.wtako.PlayerInventoryLogger.Schedulers.AutoLogger.run(AutoLogger.
java:26)
        at org.bukkit.craftbukkit.v1_7_R2.scheduler.CraftTask.run(CraftTask.java
:58)
        at org.bukkit.craftbukkit.v1_7_R2.scheduler.CraftAsyncTask.run(CraftAsyn
cTask.java:53)
        ... 3 more