Working on lifecycle.

src/main/java/appeng/core/AppEngServerStartup.java

@@ -0,0 +1,12 @@
+package appeng.core;
+
+import appeng.server.AppEngServer;
+import net.fabricmc.api.DedicatedServerModInitializer;
+
+@SuppressWarnings("unused")
+public class AppEngServerStartup implements DedicatedServerModInitializer {
+    @Override
+    public void onInitializeServer() {
+        AppEngHolder.INSTANCE = new AppEngServer();
+    }
+}

src/main/java/appeng/server/AppEngServer.java

@@ -23,23 +23,28 @@ import appeng.hooks.TickHandler;
 
 public final class AppEngServer extends AppEngBase {
 
-    private final MinecraftServer server;
+    private MinecraftServer server;
 
     private final ServerNetworkHandler networkHandler;
 
     private final TickHandler tickHandler;
 
-    public AppEngServer(MinecraftServer server) {
-        this.server = server;
+    public AppEngServer() {
         this.networkHandler = new ServerNetworkHandler();
         this.tickHandler = new TickHandler();
 
-        // For a dedicated server, the lifecycle of WorldData is much simpler
-        WorldData.onServerStarting(server);
+        ServerLifecycleEvents.SERVER_STARTING.register(this::onServerStarting);
         ServerLifecycleEvents.SERVER_STOPPING.register(s -> onServerStopping());
         ServerLifecycleEvents.SERVER_STOPPED.register(s -> onServerStopped());
     }
 
+    private void onServerStarting(MinecraftServer server) {
+        // For a dedicated server, the lifecycle of WorldData is much simpler
+        WorldData.onServerStarting(server);
+
+        this.server = server;
+    }
+
     private void onServerStopping() {
         WorldData.instance().onServerStopping();
     }

src/main/resources/fabric.mod.json

@@ -16,8 +16,8 @@
 
   "environment": "*",
   "entrypoints": {
-    "main": [],
     "client": ["appeng.core.AppEngClientStartup"],
+    "server": ["appeng.core.AppEngServerStartup"],
     "rei_plugins": ["appeng.integration.modules.jei.ReiPlugin"]
   },
   "mixins": ["appliedenergistics2.mixins.json"],