SkeletonKing Error

[19:56:18] [Server thread/INFO]: CONSOLE issued server command: /broadcast this is a default command that is broadcasted when the Skeleton King is spawned.
[19:56:18] [Craft Scheduler Thread - 8/WARN]: [EpicBosses] Plugin EpicBosses v1.2 generated an exception while executing task 34
java.lang.IllegalStateException: Asynchronous getNearbyEntities!
        at org.spigotmc.AsyncCatcher.catchOp(AsyncCatcher.java:14) ~[spigot-1.14.4.jar:git-Spigot-94af569-a3fdef8]
        at org.bukkit.craftbukkit.v1_14_R1.entity.CraftEntity.getNearbyEntities(CraftEntity.java:493) ~[spigot-1.14.4.jar:git-Spigot-94af569-a3fdef8]
        at com.songoda.epicbosses.targeting.TargetHandler.updateTarget(TargetHandler.java:55) ~[?:?]
        at com.songoda.epicbosses.targeting.TargetHandler.lambda$runTargetCycle$0(TargetHandler.java:33) ~[?:?]
        at org.bukkit.craftbukkit.v1_14_R1.scheduler.CraftTask.run(CraftTask.java:81) ~[spigot-1.14.4.jar:git-Spigot-94af569-a3fdef8]
        at org.bukkit.craftbukkit.v1_14_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:54) [spigot-1.14.4.jar:git-Spigot-94af569-a3fdef8]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_221]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_221]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_221]