Completely fix Forge (probably)

common/src/main/java/net/lerariemann/infinity/mixin/MinecraftServerMixin.java

···
         if (PlatformMethods.isModLoaded("gravity_changer_q"))
             GravityChangerCompat.changeMavity(world);
         // Invoke load world event for listeners.
-        ServerWorldEvents.LOAD.invoker().onWorldLoad((MinecraftServer) (Object) this, world);
+        PlatformMethods.onWorldLoad(this, world);
     }
 
     @Override

common/src/main/java/net/lerariemann/infinity/var/ModMaterialRules.java

···
 package net.lerariemann.infinity.var;
 
+import com.mojang.serialization.Codec;
 import com.mojang.serialization.MapCodec;
+import dev.architectury.registry.registries.DeferredRegister;
 import net.lerariemann.infinity.InfinityMod;
 import net.lerariemann.infinity.block.ModBlocks;
 import net.lerariemann.infinity.util.RandomProvider;
···
 import net.minecraft.nbt.NbtElement;
 import net.minecraft.registry.Registries;
 import net.minecraft.registry.Registry;
+import net.minecraft.registry.RegistryKeys;
 import net.minecraft.state.property.Properties;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.dynamic.CodecHolder;
···
         }
     }
 
+    public static final DeferredRegister<Codec<? extends MaterialRules.MaterialRule>> MATERIAL_RULES =
+            DeferredRegister.create(MOD_ID, RegistryKeys.MATERIAL_RULE);
+
     public static <T extends CodecHolder<? extends MaterialRules.MaterialRule>> void register(String name, T holder) {
-        Registry.register(Registries.MATERIAL_RULE, InfinityMod.MOD_ID + ":" + name, holder.codec());
+        MATERIAL_RULES.register(name, () -> holder.codec());
     }
 
     public static void registerRules() {

forge/src/main/java/net/lerariemann/infinity/forge/PlatformMethodsImpl.java

···
 import dev.architectury.registry.registries.RegistrySupplier;
 import io.netty.buffer.Unpooled;
 import net.fabricmc.fabric.api.itemgroup.v1.ItemGroupEvents;
+import net.fabricmc.fabric.mixin.registry.sync.RegistriesAccessor;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemGroup;
 import net.minecraft.item.ItemGroups;
 import net.minecraft.network.PacketByteBuf;
+import net.minecraft.registry.MutableRegistry;
 import net.minecraft.registry.Registry;
 import net.minecraft.registry.RegistryKey;
+import net.minecraft.registry.SimpleRegistry;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.world.ServerWorld;
+import net.minecraft.world.dimension.DimensionOptions;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.level.LevelEvent;
 import net.minecraftforge.fml.ModList;
···
     }
 
     public static void unfreeze(Registry<?> registry) {
-//        ((net.fabricmc.fabric.mixin.registry.sync.RegistriesAccessor) registry).invokeUnfreeze();
+        SimpleRegistry<?> writableRegistry = (SimpleRegistry<?>) registry;
+        writableRegistry.unfreeze();
     }
 
     public static void freeze(Registry<?> registry) {

forge/src/main/resources/pack.mcmeta

···
+{
+  "pack": {
+    "description": "Infinite Dimensions",
+    "forge:server_data_pack_format": 15,
+    "pack_format": 15
+  }
+}