org.bukkit.event.EventException: null
 at 
 org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
at 
 org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:589)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:576)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 org.bukkit.craftbukkit.v1_17_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:499)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.server.level.PlayerInteractManager.a(PlayerInteractManager.java:485)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.network.PlayerConnection.a(PlayerConnection.java:1527) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
at 
 net.minecraft.network.protocol.game.PacketPlayInUseItem.a(PacketPlayInUseItem.java:33)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.network.protocol.game.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.network.protocol.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:30)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.TickTask.run(SourceFile:18) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.util.thread.IAsyncTaskHandler.executeTask(SourceFile:151) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
at 
 net.minecraft.util.thread.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.util.thread.IAsyncTaskHandler.executeNext(SourceFile:125) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.MinecraftServer.bf(MinecraftServer.java:1148) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.MinecraftServer.executeNext(MinecraftServer.java:1141) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.util.thread.IAsyncTaskHandler.awaitTasks(SourceFile:134) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
at 
 net.minecraft.server.MinecraftServer.sleepForTick(MinecraftServer.java:1125)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.MinecraftServer.x(MinecraftServer.java:1054) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:305) ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at java.lang.Thread.run(Thread.java:831) [?:?]
 Caused by: java.lang.NoSuchFieldError: bO
 at fr.kestrel.duilgmc.customentities.Snail.initPathfinder(Snail.java:29) ~[?:?]
at 
 net.minecraft.world.entity.EntityInsentient.<init>(EntityInsentient.java:151)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.world.entity.EntityCreature.<init>(EntityCreature.java:17)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.world.entity.monster.EntityMonster.<init>(SourceFile:30)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at 
 net.minecraft.world.entity.monster.EntitySilverfish.<init>(EntitySilverfish.java:39)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 at fr.kestrel.duilgmc.customentities.Snail.<init>(Snail.java:19) ~[?:?]
 at fr.kestrel.duilgmc.events.GetBark.getBark(GetBark.java:31) ~[?:?]
 at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
 at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78) ~[?:?]
 at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
 at java.lang.reflect.Method.invoke(Method.java:567) ~[?:?]
at 
 org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306)
 ~[spigot-1.17.1.jar:3227-Spigot-3c1fc60-a0a37f4]
 ... 20 more

public class Snail extends EntitySilverfish implements Listener {
    public Snail(Location loc) {
        super(EntityTypes.aA, ((CraftWorld)loc.getWorld()).getHandle());
        /*More code*/
    }
    @Override
    protected void initPathfinder() {
        this.bO.a(1, new PathfinderGoalFloat(this));
        this.bO.a(2, new PathfinderGoalLookAtPlayer(this, EntityHuman.class, 6.0F));
        this.bO.a(3, new PathfinderGoalRandomLookaround(this));
    }
}