[23:59:15 WARN]: [CraftZ] Task #17 for CraftZ v1.0 generated an exception
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:839) ~[?:1.7.0_71]
	at java.util.HashMap$EntryIterator.next(HashMap.java:880) ~[?:1.7.0_71]
	at java.util.HashMap$EntryIterator.next(HashMap.java:878) ~[?:1.7.0_71]
	at craftZ.util.PlayerManager.onServerTick(PlayerManager.java:207) ~[?:?]
	at craftZ.CraftZ$2.run(CraftZ.java:173) ~[?:?]
	at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:694) [spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:623) [spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:526) [spigot-1.8-R0.1-SNAPSHOT-12-7-14.jar:git-Spigot-b8f6402-a646500]
	at java.lang.Thread.run(Thread.java:745) [?:1.7.0_71]