Client log: https://drive.google.com/file/d/0B9RqL-zfpcJWcGtESzlTc1dSREk/view?usp=sharing
Server log: https://drive.google.com/file/d/0B9RqL-zfpcJWajFfSUxsek9YaTg/view?usp=sharing
(very large logs ... too large for pastebin)
The id 98 is stone bricks in vanilla Minecraft.
When I join my server the message
is displayed by the client, on the login-error screen (with the dirt in background), but there is no crash. The server just sees the connexion closed.
I have tested with Forge 1408 and 1448, and KCauldron 1408.91 and 1488.121, with always the same result. I have the KC fix for Mobius core, and the libraries were installed with KCauldron-1448.191.
Both server and client are running Java 7u80, with 6GB of RAM and 512MB of PermGen.
If you need my server config, or the whole directory, just ask me.
I really don't know where is this error coming from ...