Bład z List, ArrayList

Mam sobie obiekt RawBlock:

public class RawBlock {

    private Location location;
    private Material block;
    private Long time;

    public RawBlock(Location location, Material block, Long time){
        this.location = location;
        this.block = block;
        this.time = time;
        RawBlockUtil.add(this);
    }

    public Location getLocation() {
        return location;
    }

    public Material getBlock() {
        return block;
    }

    public Long getTime() {
        return time;
    }
}

I mam do niego klase RawBlockUtil:

public class RawBlockUtil {

    public static List<RawBlock> blockList = new ArrayList<>();

    public static void add(RawBlock block){
        for(RawBlock rawBlock : RawBlockUtil.blockList){
            if(block.getLocation() == rawBlock.getLocation()){
                return;
            }
        }
        RawBlockUtil.blockList.add(block);
    }

    public static void remove(RawBlock block){
        if(RawBlockUtil.blockList.contains(block)){
            RawBlockUtil.blockList.remove(block);
        }
        return;
    }

    public static Integer debug(){
        Integer amount = 0;
        for(RawBlock rawBlock : RawBlockUtil.blockList){
            rawBlock.getLocation().getBlock().setType(rawBlock.getBlock());
            RawBlockUtil.blockList.remove(rawBlock);
            amount++;
        }
        return amount;
    }
}

Przykładowe tworzenie nowego obiektu:

public void onBreak(BlockBreakEvent event) {
        if(event.getBlock().getType() == Material.IRON_ORE || event.getBlock().getType() == Material.GOLD_ORE || event.getBlock().getType() == Material.DIAMOND_ORE || event.getBlock().getType() == Material.EMERALD_ORE || event.getBlock().getType() == Material.LAPIS_ORE || event.getBlock().getType() == Material.REDSTONE_ORE || event.getBlock().getType() == Material.COAL_ORE){
            Player player = event.getPlayer();
            long time = player.hasPermission("rawcore.boosters.generator") ? 20*60*30L : 20*60*45L;
            new RawBlock(event.getBlock().getLocation(), event.getBlock().getType(), time);

Kiedy chce wykonać metodę z tym obiektem (np. debug()) to wyrzuca błąd z tą linijką:

for(RawBlock rawBlock : RawBlockUtil.blockList)

A oto błąd:

Unexpected exception while parsing console command "oregenerator zregeneruj"
org.bukkit.command.CommandException: Unhandled exception executing command 'oregenerator' in plugin rawCore vv1.1
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:648) ~[spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchServerCommand(CraftServer.java:634) [spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at net.minecraft.server.v1_12_R1.DedicatedServer.aP(DedicatedServer.java:444) [spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:407) [spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        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 pl.krejzolekpro.rawcore.obejcts.utils.RawBlockUtil.debug(RawBlockUtil.java:30) ~[?:?]
        at pl.krejzolekpro.rawcore.commands.GeneratorCommand.onCommand(GeneratorCommand.java:15) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-1.12.2.jar:git-Spigot-2086bb0-d0a3620]
        ... 8 more

Pierwszy raz spotkałem się z takim czymś i nie wiem jak sobie z tym poradzić.

Sllnik: Spigot 1.12.2

Java 10.