Hi,

I made my own modpack with Twitch including this mod. But the (one) other person I'm playing with was getting constantly disconnected after a short time and huge lags. The problem is only inside the Betweenlands dimension. No problems on my client. The server is running on my computer.

I gave the modpack to the other person by exporting it from Twitch and the server is set up by using the forge installer (I guess that is a "vanilla" server?) and then copying the client "config" and "mods" folder into the server (excluding OptiFine). I then start it with java -jar -Xmx5G forge-[...].jar nogui

I used Minecraft 1.12.2 and the newest versions of OptiFine (1.12.2 HD U F5), TheBetweenlands (3.6.1) and Forge (2854). We disabled all other mods and, only after having TheBetweenlands and OptiFine left, have "fixed" the issue by disabling OptiFine.

After that we downgraded Forge and OptiFine two times but the issue didn't go away. While doing so I also reinstalled the server from scratch two times. Shaders are disabled of course and the error logs of the client and server are not helpful. It's just logging that the player lost connection. Regarding Windows we tried disabling the firewall and switching from ZeroTier to Hamachi but that didn't help either. We also both have more than enough RAM and allocated 5GB to the client.

I have just returned to Minecraft after many years. Forge, Twitch-App and all that are new to me so maybe it's something obvious?