CRAFTBOOK-3049 - Reported by ericgol

Keep hitting this Unhandled Exception with CB3.9b3 and Async threads at startup.. here's the stack trace: [09:51:29 WARN]: org.apache.commons.lang.UnhandledException: Plugin CraftBook v3.9-SNAPSHOT:3873-edf1456,master generated an exception while executing
task 44
at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.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: org.bukkit.Server.getOnlinePlayers()Ljava/util/Collection;
at com.sk89q.craftbook.bukkit.Metrics.postPlugin(Metrics.java:335)
at com.sk89q.craftbook.bukkit.Metrics.access$400(Metrics.java:56)
at com.sk89q.craftbook.bukkit.Metrics$1.run(Metrics.java:223)
at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftTask.run(CraftTask.java:53)
at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
... 3 more

Comment by me4502

You need to update bukkit.