ERORR

[11:37:51] [Server thread/INFO]: [PrisonUtils] Enabling PrisonUtils v1.6.12
[11:37:51] [Server thread/ERROR]: Error occurred while enabling PrisonUtils v1.6.12 (Is it up to date?)
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
	at me.mrCookieSlime.PrisonUtils.PrisonUtils.onEnable(PrisonUtils.java:95) ~[?:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:291) ~[spigot.jar:git-Spigot-604e046-69e196f]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340) [spigot.jar:git-Spigot-604e046-69e196f]
	at me.incomprehendable.dev.pwp.transparentlisteners.PerWorldPluginLoader.enablePlugin(PerWorldPluginLoader.java:141) [PerWorldPlugins.jar:?]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot.jar:git-Spigot-604e046-69e196f]
	at org.bukkit.craftbukkit.v1_9_R1.CraftServer.loadPlugin(CraftServer.java:361) [spigot.jar:git-Spigot-604e046-69e196f]
	at org.bukkit.craftbukkit.v1_9_R1.CraftServer.enablePlugins(CraftServer.java:321) [spigot.jar:git-Spigot-604e046-69e196f]
	at net.minecraft.server.v1_9_R1.MinecraftServer.t(MinecraftServer.java:411) [spigot.jar:git-Spigot-604e046-69e196f]
	at net.minecraft.server.v1_9_R1.MinecraftServer.l(MinecraftServer.java:376) [spigot.jar:git-Spigot-604e046-69e196f]
	at net.minecraft.server.v1_9_R1.MinecraftServer.a(MinecraftServer.java:331) [spigot.jar:git-Spigot-604e046-69e196f]
	at net.minecraft.server.v1_9_R1.DedicatedServer.init(DedicatedServer.java:269) [spigot.jar:git-Spigot-604e046-69e196f]
	at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:522) [spigot.jar:git-Spigot-604e046-69e196f]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_73]