fix

src/Visual_DVM_2021/Passes/All/AbortDVMPackage.java

@@ -36,6 +36,6 @@ public class AbortDVMPackage extends TestingSystemPass<DVMPackage> {
     }
     @Override
     protected void ServerAction() throws Exception {
-        Command(new ServerExchangeUnit_2021(ServerCode.PublishObject, "", packageToKill));
+        Command(new ServerExchangeUnit_2021(ServerCode.PublishObject, null, packageToKill));
     }
 }