net.minecraft.server.v1_14_R1.ReportedException: Ticking entity 
at net.minecraft.server.v1_14_R1.MinecraftServer.b(MinecraftServer.java:1070) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.DedicatedServer.b(DedicatedServer.java:396) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.a(MinecraftServer.java:959) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:804) [server.jar:git-Spigot-d05d3c1-087a2cf] 
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171] 
Caused by: java.util.ConcurrentModificationException 
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1442) ~[?:1.8.0_171] 
at java.util.HashMap$KeyIterator.next(HashMap.java:1466) ~[?:1.8.0_171] 
at java.lang.Iterable.forEach(Iterable.java:74) ~[?:1.8.0_171] 
at net.minecraft.server.v1_14_R1.ChunkMapDistance.a(ChunkMapDistance.java:102) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.tickDistanceManager(ChunkProviderServer.java:202) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkFutureMainThread(ChunkProviderServer.java:142) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:89) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:212) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.IWorldReader.getChunkAt(SourceFile:106) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:207) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getType(World.java:548) ~[server.jar:git-Spigot-d05d3c1-087a2cf]
at net.minecraft.server.v1_14_R1.Navigation.b(SourceFile:44) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.Navigation.a(SourceFile:73) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.PathfinderGoalMeleeAttack.a(SourceFile:52) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.PathfinderGoalWrapped.a(SourceFile:22) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.Iterator.forEachRemaining(Iterator.java:116) ~[?:1.8.0_171] 
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[?:1.8.0_171] 
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151) ~[?:1.8.0_171] 
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418) ~[?:1.8.0_171] 
at net.minecraft.server.v1_14_R1.PathfinderGoalSelector.doTick(SourceFile:69) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.doTick(EntityInsentient.java:649) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityLiving.movementTick(EntityLiving.java:2456) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.movementTick(EntityInsentient.java:502) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityMonster.movementTick(SourceFile:39) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntitySkeletonAbstract.movementTick(EntitySkeletonAbstract.java:85) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityLiving.tick(EntityLiving.java:2292) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.tick(EntityInsentient.java:273) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityMonster.tick(SourceFile:51) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.WorldServer.entityJoinedWorld(WorldServer.java:570) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.a(World.java:745) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.WorldServer.doTick(WorldServer.java:346) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.b(MinecraftServer.java:1057) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
... 4 more 
> [14:07:14] [Server thread/ERROR]: Cause of unexpected exception was 
java.util.ConcurrentModificationException: null 
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1442) ~[?:1.8.0_171] 
at java.util.HashMap$KeyIterator.next(HashMap.java:1466) ~[?:1.8.0_171] 
at java.lang.Iterable.forEach(Iterable.java:74) ~[?:1.8.0_171] 
at net.minecraft.server.v1_14_R1.ChunkMapDistance.a(ChunkMapDistance.java:102) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.tickDistanceManager(ChunkProviderServer.java:202) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkFutureMainThread(ChunkProviderServer.java:142) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:89) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:212) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.IWorldReader.getChunkAt(SourceFile:106) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:207) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.getType(World.java:548) ~[server.jar:git-Spigot-d05d3c1-087a2cf]
at net.minecraft.server.v1_14_R1.Navigation.b(SourceFile:44) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.Navigation.a(SourceFile:73) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.PathfinderGoalMeleeAttack.a(SourceFile:52) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.PathfinderGoalWrapped.a(SourceFile:22) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[?:1.8.0_171] 
at java.util.Iterator.forEachRemaining(Iterator.java:116) ~[?:1.8.0_171] 
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[?:1.8.0_171] 
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151) ~[?:1.8.0_171] 
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174) ~[?:1.8.0_171] 
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:1.8.0_171] 
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418) ~[?:1.8.0_171] 
at net.minecraft.server.v1_14_R1.PathfinderGoalSelector.doTick(SourceFile:69) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.doTick(EntityInsentient.java:649) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityLiving.movementTick(EntityLiving.java:2456) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.movementTick(EntityInsentient.java:502) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityMonster.movementTick(SourceFile:39) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntitySkeletonAbstract.movementTick(EntitySkeletonAbstract.java:85) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityLiving.tick(EntityLiving.java:2292) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityInsentient.tick(EntityInsentient.java:273) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.EntityMonster.tick(SourceFile:51) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.WorldServer.entityJoinedWorld(WorldServer.java:570) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.World.a(World.java:745) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.WorldServer.doTick(WorldServer.java:346) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.b(MinecraftServer.java:1057) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.DedicatedServer.b(DedicatedServer.java:396) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.a(MinecraftServer.java:959) ~[server.jar:git-Spigot-d05d3c1-087a2cf] 
at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:804) [server.jar:git-Spigot-d05d3c1-087a2cf] 
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171] 
> [14:07:14] [Server thread/ERROR]: This crash report has been saved to: /home/hosting/servers/220892/./crash-reports/crash-2019-07-19_14.07.14-server.txt