Bukkit

What steps will reproduce the problem?
1.Running Around
2.
3.

What is the expected output? What do you see instead?
Server runs fine it just give this error all the time nor sure why! But the server and the plugin works just fine with the errors.

What version of the product are you using?
1.8.0

Do you have an error log of what happened?
[SEVERE] Exception in thread "pool-1-thread-119"
org.apache.commons.lang.UnhandledException: Plugin SunBurn2 v1.8.0 generated an exception while executing task 11
at org.bukkit.craftbukkit.v1_4_6.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.next(Unknown Source)
at org.bukkit.craftbukkit.v1_4_6.CraftWorld.getPlayers(CraftWorld.java:627)
at org.bukkit.craftbukkit.v1_4_6.CraftWorld.setFullTime(CraftWorld.java:439)
at org.bukkit.craftbukkit.v1_4_6.CraftWorld.setTime(CraftWorld.java:428)
at com.github.vsams14.sunburn.Util.lockTime(Util.java:223)
at com.github.vsams14.sunburn.Burn.BurnMain(Burn.java:28)
at com.github.vsams14.sunburn.Main$5.run(Main.java:175)
at org.bukkit.craftbukkit.v1_4_6.scheduler.CraftTask.run(CraftTask.java:53)
at org.bukkit.craftbukkit.v1_4_6.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
... 3 more

Please provide any additional information below.
i think its from when i generate chunks new and old it gives off this message. Not sure why but the server and the plugin still works fine.

I have the same issue. Are you running any other environmental plugins?