[21:02:25 WARN]: Exception in thread "MyZ Async Tick Thread - 55"
[21:02:25 WARN]: org.apache.commons.lang.UnhandledException: Plugin Skript v2.1.2 generated an exception while executing task 64
        at org.bukkit.craftbukkit.v1_9_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
        at ch.njol.skript.Metrics.postPlugin(Metrics.java:347)
        at ch.njol.skript.Metrics$1.run(Metrics.java:235)
        at org.bukkit.craftbukkit.v1_9_R1.scheduler.CraftTask.run(CraftTask.java:71)
        at org.bukkit.craftbukkit.v1_9_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
        ... 3 more