Use FMLServerStartingEvent to register command

build.gradle

@@ -37,7 +37,7 @@ curseforge {
     project {
         id = '227449'
         changelog  = ''
-        releaseType = 'release'
+        releaseType = 'beta'
         addGameVersion '1.8.9'
     }
 }

src/main/java/ljfa/tntutils/TNTUtils.java

@@ -6,14 +6,12 @@
 
 import ljfa.tntutils.command.CommandExplosion;
 import ljfa.tntutils.proxy.CommonProxy;
-import net.minecraft.command.ServerCommandManager;
-import net.minecraft.server.MinecraftServer;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.SidedProxy;
 import net.minecraftforge.fml.common.event.FMLInitializationEvent;
 import net.minecraftforge.fml.common.event.FMLPostInitializationEvent;
 import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
-import net.minecraftforge.fml.common.event.FMLServerStartedEvent;
+import net.minecraftforge.fml.common.event.FMLServerStartingEvent;
 
 @Mod(modid = Reference.MODID, name = Reference.MODNAME, version = Reference.VERSION, acceptableRemoteVersions = "*",
     guiFactory = Reference.GUI_FACTORY_CLASS, dependencies = "required-after:tnt_utilities_core",
@@ -47,11 +45,9 @@ public void postInit(FMLPostInitializationEvent event) {
     }
 
     @Mod.EventHandler
-    public void serverStarted(FMLServerStartedEvent event) {
+    public void serverStarting(FMLServerStartingEvent event) {
         if(Config.explosionCommand) {
-            MinecraftServer server = MinecraftServer.getServer();
-            ServerCommandManager commandManager = (ServerCommandManager)server.getCommandManager();
-            commandManager.registerCommand(new CommandExplosion());
+            event.registerServerCommand(new CommandExplosion());
         }
     }
 }