@EventHandler(priority = EventPriority.NORMAL)
public void onPlayerJoinEvent(PlayerJoinEvent event) {
    ProtocolManager protocolManager = ProtocolLibrary.getProtocolManager();
    Player player = event.getPlayer();

    PacketContainer fakeExplosion = new PacketContainer(PacketType.Play.Server.EXPLOSION);
    fakeExplosion.getDoubles()
            .write(0, player.getLocation().getX())
            .write(1, player.getLocation().getY())
            .write(2, player.getLocation().getZ());
    fakeExplosion.getFloat().write(0, 3.0F);
    fakeExplosion.getBlockPositionCollectionModifier().write(0, new ArrayList<>());
    fakeExplosion.getVectors().write(0, player.getVelocity().add(new Vector(1, 1, 1)));

    protocolManager.sendServerPacket(player, fakeExplosion);
}

[Server thread/ERROR]: Could not pass event PlayerJoinEvent to shandebaokesi v1.0-SNAPSHOT
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-api-1.21.5-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-api-1.21.5-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:601) ~[spigot-api-1.21.5-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:588) ~[spigot-api-1.21.5-R0.1-SNAPSHOT.jar:?]
        at net.minecraft.server.players.PlayerList.a(PlayerList.java:298) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.network.ServerConfigurationPacketListenerImpl.a(ServerConfigurationPacketListenerImpl.java:168) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.network.protocol.configuration.ServerboundFinishConfigurationPacket.a(SourceFile:22) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.network.protocol.configuration.ServerboundFinishConfigurationPacket.a(SourceFile:8) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.network.protocol.PlayerConnectionUtils.lambda$ensureRunningOnSameThread$0(PlayerConnectionUtils.java:35) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.TickTask.run(SourceFile:18) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.util.thread.IAsyncTaskHandler.d(SourceFile:164) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.util.thread.IAsyncTaskHandlerReentrant.d(SourceFile:23) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1290) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:206) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.util.thread.IAsyncTaskHandler.B(SourceFile:138) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.bv(MinecraftServer.java:1273) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.B(MinecraftServer.java:1266) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.util.thread.IAsyncTaskHandler.b(SourceFile:147) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1223) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.w_(MinecraftServer.java:1233) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1076) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:325) ~[spigot-1.21.5-R0.1-SNAPSHOT.jar:4504-Spigot-270012a-dacd062]
        at java.base/java.lang.Thread.run(Thread.java:1575) [?:?]
Caused by: com.comphenix.protocol.reflect.FieldAccessException: Field index 0 is out of bounds for length 0
        at com.comphenix.protocol.reflect.FieldAccessException.fromFormat(FieldAccessException.java:49) ~[?:?]
        at com.comphenix.protocol.reflect.StructureModifier.write(StructureModifier.java:318) ~[?:?]
        at sandboxmode.widget.TestWidget.onPlayerJoinEvent(TestWidget.java:68) ~[?:?]
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
        at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-api-1.21.5-R0.1-SNAPSHOT.jar:?]
        ... 22 more