Placing an Integrated Dynamics Proxy or Materializer on a dedicated server causes client to crash

[NioXen]

Modpack

FTB Unstable 1.21

Modpack version

1.2.0

Launcher

FTB App

Has the pack been modified

No

Log Files

https://pste.ch/susofivomi.coffeescript

Describe the bug

When running a dedicated server (using the provided server files) and a connected player tries to place either a Materializer or a Proxy from the Integrated Dynamics mod pack, they are disconnected with a Null Pointer Exception:

java.lang.NullPointerException: Cannot invoke "net.minecraft.server.MinecraftServer.registryAccess()" because the return value of "net.neoforged.neoforge.server.ServerLifecycleHooks.getCurrentServer()" is null

The server remains running and stable, with the only server-side error being connection lost:

[13:20:33] [Netty Server IO #1/ERROR] [minecraft/Connection]: Exception caught in connection
java.net.SocketException: Connection reset

When running locally (no server) the blocks can be placed and used successfully. If a world is loaded on the server that already has these blocks placed, then no client can connect to the server.

Steps to reproduce

1. Download the dedicated server files from https://www.feed-the-beast.com/modpacks/124-ftb-unstable-121?tab=versions
2. Run the server locally using run.bat with a new world
3. Launch Unstable 1.21 from the FTB App
4. Connect to the server using localhost as the direct connect address
5. Give player a Proxy from Integrated Dynamics /give <PLAYER> integrateddynamics:proxy
6. Try to place the Proxy in the world and be disconnected.

Expected behaviour

Proxy/Materializer are successfully placed and can be used

Screenshots

No response

Additional information

No response