src/de/steamwar/bungeecore/listeners/mods/Fabric.java

@@ -58,7 +58,7 @@ public class Fabric extends BasicListener {
     public void onServerSwitch(ServerSwitchEvent event) {
         if(Subserver.getSubserver(event.getPlayer()) != null
                 && Subserver.getSubserver(event.getPlayer()).getType() == Servertype.ARENA
-                && Storage.fabricPlayers.contains(event.getPlayer())) {
+                && isFabric(event.getPlayer())) {
             event.getPlayer().connect(BungeeCore.get().getProxy().getServerInfo(BungeeCore.LOBBY_SERVER));
             BungeeCore.send(event.getPlayer(), BungeeCore.CHAT_PREFIX + "§cDu kannst nicht auf die Arena mit Fabric");
         }