Migrated from: https://dev.bukkit.org/projects/shopkeepers/issues/131

Originally posted by RasCas (May 7, 2013):

2013-05-07 06:17:58 [WARNING] [Shopkeepers] Task #6471 for Shopkeepers v1.13.2 generated an exception
java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.remove(Unknown Source)
    at com.nisovin.shopkeepers.ShopkeepersPlugin$4.run(ShopkeepersPlugin.java:583)
    at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftTask.run(CraftTask.java:53)
    at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
    at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:513)
    at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
    at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
    at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
    at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)Running Bukkit 1.52 r01

Originally closed by nisovin (Jul 5, 2013)

Originally commented by RasCas (May 7, 2013):

It happens, when you name a shop(keeper) by clicking the anvil

        Edited May 7, 2013