src/de/steamwar/bungeecore/listeners/NonFabricFabricCheck.java

@@ -41,6 +41,7 @@ public class NonFabricFabricCheck extends BasicListener {
     private final Set<UUID> usingFabric = new HashSet<>();
 
     private final Set<ProxiedPlayer> checking = new HashSet<>();
+    private final Set<ProxiedPlayer> vanilla = new HashSet<>();
 
     {
         BungeeCord.getInstance().getScheduler().schedule(BungeeCore.get(), usingFabric::clear, 0, 15, TimeUnit.MINUTES);
@@ -52,14 +53,23 @@ public class NonFabricFabricCheck extends BasicListener {
         if(!(sender instanceof ProxiedPlayer))
             return;
 
-        if(!e.getTag().equals("minecraft:brand"))
+        ProxiedPlayer p = (ProxiedPlayer) sender;
-            return;
+        if (e.getTag().equals("minecraft:register") && new String(e.getData()).contains("fabric-screen-handler-api-v1:open_screen")) {
-
+            BungeeCord.getInstance().getScheduler().schedule(BungeeCore.get(), () -> {
-        if(!new String(e.getData()).equals("vanilla")){
+                if (!sender.isConnected()) return;
+                if (!vanilla.remove(p)) return;
+                if (Storage.fabricCheckedPlayers.containsKey(p)) return;
+                p.disconnect(Message.parse("MOD_USE_MODSENDER", p));
+            }, 25, TimeUnit.SECONDS);
             return;
         }
 
-        ProxiedPlayer p = (ProxiedPlayer) sender;
+        if(!e.getTag().equals("minecraft:brand"))
+            return;
+
+        if(!new String(e.getData()).equals("vanilla"))
+            return;
+        vanilla.add(p);
 
         BungeeCord.getInstance().getScheduler().schedule(BungeeCore.get(), () -> {
             if (!p.isConnected()) return;
@@ -82,5 +92,6 @@ public class NonFabricFabricCheck extends BasicListener {
         if (checking.remove(e.getPlayer())) {
             usingFabric.add(e.getPlayer().getUniqueId());
         }
+        vanilla.remove(e.getPlayer());
     }
 }