Mod Version: 1.10.2-4.1.6
Modpack: Resonant Rise 4 Dev a.1.1.0

If the server uses the new line character (\n), the entire message won't be shown to all clients with BetterMinecraftChat.

This is a sample Sponge code snippet that helps reproducing the issue:

@Listener(order=Order.POST)
public void onPlayerJoin(ClientConnectionEvent.Join event) {
  event.getTargetEntity().sendMessage(Text.of("This is the first line", Text.NEW_LINE, "This is the second line"));
}

Thanks. Keep up the good work!

Mod is being rewritten to work better at the moment, this will likely be fixed automatically when I'm done

This was fixed as part of the rewrite for Minecraft 1.11.2.