SpongeForge and Bungee Cord

Hi, I’m currently trying to connect several moded servers with Sponge.

I used to post a topic to ask how I could send messages with plugin channels.

Sponge.getChannelRegistrar().getOrCreateRaw(this, "BungeeCord")
` .sendTo(player, buf -> buf.writeUTF("Connect").writeUTF("lobby2"));`

I am so at this point, but when connecting the player, I get this error that closes the server.

[21:06:55] [Server thread/INFO] [FML]: Connection received without FML marker, assuming vanilla.
[21:06:55] [Server thread/INFO] [FML]: Opening channel which already seems to have a state set. This is a vanilla connection. Handshake handler will stop now
[21:06:55] [Server thread/INFO] [FML]: [Server thread] Server side vanilla connection established

For information I activated IP forwarding, I do not know if it can come from there.
I understood that there were problems and that it did not work before, but that it was settled today.

If it’s not fixed, how can I do it?
Is this topic still relevant? https://forums.spongepowered.org/t/spongepls-bungeecord-forge-support/9891

I have this error in game :

Could not connect to a default or fallback server, please try again later : io.netty.channel.AbstractChannel$AnnotatedConnectExecption

That’s not an error message. That’s an info message, saying a vanilla client connected successfully.
Do you have SpongePls installed?

But after this message, the server was closing.
It does not happen anymore, and I have not changed anything.

No, I did not install SpongePls, it’s necessary ?

I don’t know why it would be closing, since, again, this isn’t an error message, or even anything out of the ordinary.
Yes, SpongePls is necessary. You can have either IP forwarding or Forge with regular Bungee; to use both, you need SpongePls.