多次从ArrayList中删除时出现异常Java错误。（非法国家例外）

Question

我在谷歌上搜索了很久，似乎找不到解决办法。我做错了什么？我的问题在于标题。以下是我得到的一个例外：

java.lang.IllegalStateException
at java.util.ArrayList$Itr.remove(Unknown Source)
at me.herp.derp.client.Config.updateItem(Config.java:24)
at me.herp.derp.client.Commands.parseCommand(Commands.java:23)
at me.herp.derp.client.ChatCommands.handleChatcommand(ChatCommands.java:29)
at net.minecraft.src.EntityClientPlayerMP.sendChatMessage(EntityClientPlayerMP.java:171)
at net.minecraft.src.GuiChat.keyTyped(GuiChat.java:104)
at net.minecraft.src.GuiScreen.handleKeyboardInput(GuiScreen.java:227)
at net.minecraft.src.GuiScreen.handleInput(GuiScreen.java:176)
at net.minecraft.client.Minecraft.runTick(Minecraft.java:1494)
at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:843)
at net.minecraft.client.Minecraft.run(Minecraft.java:768)
at java.lang.Thread.run(Unknown Source)

这是我的代码：

public static void updateItem(String item, String value)
{
    if (!hasValue(item))
    {
        addItem(item, value);
        return;
    }
    for (ConfigItem c : configItems)
    {
        if (c.ITEM.equals(item))
        {
            configItems.iterator().remove();
            break;
        }
    }
    ConfigFile.saveConfig();
}