src/de/steamwar/bungeecore/commands/BauCommand.java

@@ -210,6 +210,11 @@ public class BauCommand {
                         return;
                     }
                     subserver.stop();
+                    try {
+                        Thread.sleep(200); // Wait until possible testarena-World has been deleted
+                    } catch (InterruptedException e) {
+                        throw new SecurityException("Subserver stop interrupted", e);
+                    }
                     break;
                 }
             }