ShutdownError

[17:52:37 INFO]: Stopping the server
[17:52:37 INFO]: Stopping server
[17:52:37 INFO]: [Iris] Disabling Iris v1.9.8
[17:52:37 INFO]: Iris is being shutdown. Removing its hooks and listeners...
[17:52:37 ERROR]: Could not pass event PluginDisableEvent to Atlas v1.3.7
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.java.JavaPluginLoader.disablePlugin(JavaPluginLoader.java:355) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.disablePlugin(SimplePluginManager.java:424) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.plugin.SimplePluginManager.disablePlugins(SimplePluginManager.java:417) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.disablePlugins(CraftServer.java:345) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.MinecraftServer.stop(MinecraftServer.java:464) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:612) [spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_211]
Caused by: java.util.ConcurrentModificationException
        at java.util.TreeMap$KeySpliterator.forEachRemaining(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:1.8.0_211]
        at java.util.stream.ReferencePipeline.forEach(Unknown Source) ~[?:1.8.0_211]
        at cc.funkemunky.api.events.EventManager.unregisterAll(EventManager.java:42) ~[?:?]
        at cc.funkemunky.api.listeners.PluginShutdownListeners.onEvent(PluginShutdownListeners.java:22) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot-1.11.2.jar:git-Spigot-3fb9445-6e3cec8]
        ... 10 more