Error PerWorldInventory

[14:12:44 WARN]: [PerWorldInventory] Plugin PerWorldInventory v1.5.8 generated an exception while executing task 64
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
	at me.gnat008.perworldinventory.Metrics.postPlugin(Metrics.java:335) ~[?:?]
	at me.gnat008.perworldinventory.Metrics.access$400(Metrics.java:57) ~[?:?]
	at me.gnat008.perworldinventory.Metrics$1.run(Metrics.java:223) ~[?:?]
	at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:76) ~[spigot-1.12.2.jar:git-Spigot-2086bb0-8cc5a7e]
	at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52) [spigot-1.12.2.jar:git-Spigot-2086bb0-8cc5a7e]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_172]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_172]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_172]