[15:23:41] [Server thread/WARN]: [Prison] Task #37 for Prison v2.0 generated an exception
java.lang.NoSuchMethodError: net.milkbowl.vault.economy.Economy.getBalance(Lorg/bukkit/OfflinePlayer;)D
at me.sirfaizdat.prison.ranks.events.BalanceChangeListener$1.run(BalanceChangeListener.java:37) ~[?:?]
at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftTask.run(CraftTask.java:58) ~[spigot.jar:git-Spigot-1493]
at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345) [spigot.jar:git-Spigot-1493]
at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:635) [spigot.jar:git-Spigot-1493]
at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:283) [spigot.jar:git-Spigot-1493]
at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:583) [spigot.jar:git-Spigot-1493]
at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:489) [spigot.jar:git-Spigot-1493]
at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1493]