diff --git a/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java b/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
index 92bc66c..0614606 100644
--- a/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
+++ b/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
@@ -22,7 +22,7 @@ public abstract class ExtensionBase extends IExtension {
     protected final Map<Integer, List<MessageListener>> incomingMessageListeners = new HashMap<>();
     protected final Map<Integer, List<MessageListener>> outgoingMessageListeners = new HashMap<>();
 
-    protected PacketInfoManager packetInfoManager = new PacketInfoManager(new ArrayList<>()); // empty
+    volatile PacketInfoManager packetInfoManager = PacketInfoManager.EMPTY;
 
     /**
      * Register a listener on a specific packet Type
@@ -131,7 +131,7 @@ public abstract class ExtensionBase extends IExtension {
         return onConnectionObservable;
     }
 
-    protected void setPacketInfoManager(PacketInfoManager packetInfoManager) {
+    void setPacketInfoManager(PacketInfoManager packetInfoManager) {
         this.packetInfoManager = packetInfoManager;
     }
 
diff --git a/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java b/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
index 5310cd0..9ac3447 100644
--- a/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
+++ b/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
@@ -1,5 +1,6 @@
 package gearth.extensions;
 
+import gearth.services.packet_info.PacketInfoManager;
 import javafx.application.Platform;
 import javafx.stage.Stage;
 import gearth.protocol.HMessage;
@@ -47,6 +48,11 @@ public abstract class ExtensionForm extends ExtensionBase {
         extension.onConnect(listener);
     }
 
+    @Override
+    public PacketInfoManager getPacketInfoManager() {
+        return extension.getPacketInfoManager();
+    }
+
     protected void onShow(){};
     protected void onHide(){};
 
diff --git a/G-Earth/src/main/java/gearth/services/internal_extensions/blockreplacepackets/BlockAndReplacePackets.java b/G-Earth/src/main/java/gearth/services/internal_extensions/blockreplacepackets/BlockAndReplacePackets.java
index 9321bb0..a30e3fe 100644
--- a/G-Earth/src/main/java/gearth/services/internal_extensions/blockreplacepackets/BlockAndReplacePackets.java
+++ b/G-Earth/src/main/java/gearth/services/internal_extensions/blockreplacepackets/BlockAndReplacePackets.java
@@ -68,9 +68,7 @@ public class BlockAndReplacePackets extends ExtensionForm {
         txt_replacement.textProperty().addListener(event -> Platform.runLater(this::refreshOptions));
         txt_value.textProperty().addListener(event -> Platform.runLater(this::refreshOptions));
 
-        refreshOptions();
         cmb_type.requestFocus();
-
     }
 
     private String getVal() {
@@ -80,8 +78,8 @@ public class BlockAndReplacePackets extends ExtensionForm {
 
         if (type.endsWith("packet")) {
             HMessage.Direction dir = side.equals("Outgoing") ? HMessage.Direction.TOSERVER : HMessage.Direction.TOCLIENT;
-            PacketInfo fromName = packetInfoManager.getPacketInfoFromName(dir, val);
-            PacketInfo fromHash = packetInfoManager.getPacketInfoFromHash(dir, val);
+            PacketInfo fromName = getPacketInfoManager().getPacketInfoFromName(dir, val);
+            PacketInfo fromHash = getPacketInfoManager().getPacketInfoFromHash(dir, val);
             if (fromName != null) {
                 val = fromName.getHeaderId() +"";
             }
@@ -208,6 +206,8 @@ public class BlockAndReplacePackets extends ExtensionForm {
 
         intercept(HMessage.Direction.TOSERVER, messageListener);
         intercept(HMessage.Direction.TOCLIENT, messageListener);
+
+        refreshOptions();
     }
 
     @Override
@@ -231,7 +231,7 @@ public class BlockAndReplacePackets extends ExtensionForm {
 
     public void click_btnAddRule(ActionEvent actionEvent) {
         BlockReplaceRule rule = RuleFactory.getRule(cmb_type.getSelectionModel().getSelectedItem(),
-                cmb_side.getSelectionModel().getSelectedItem(), getVal(), txt_replacement.getText(), packetInfoManager);
+                cmb_side.getSelectionModel().getSelectedItem(), getVal(), txt_replacement.getText(), getPacketInfoManager());
         rules.add(rule);
         rule.onDelete(observable -> rules.remove(rule));
         new RuleContainer(rule, vbox);
diff --git a/G-Earth/src/main/java/gearth/services/internal_extensions/packetinfoexplorer/PacketInfoExplorer.java b/G-Earth/src/main/java/gearth/services/internal_extensions/packetinfoexplorer/PacketInfoExplorer.java
index 337fabf..4b70ca2 100644
--- a/G-Earth/src/main/java/gearth/services/internal_extensions/packetinfoexplorer/PacketInfoExplorer.java
+++ b/G-Earth/src/main/java/gearth/services/internal_extensions/packetinfoexplorer/PacketInfoExplorer.java
@@ -111,7 +111,7 @@ public class PacketInfoExplorer extends ExtensionForm {
     @Override
     protected void initExtension() {
         onConnect((host, port, hotelversion, clientIdentifier, clientType) -> {
-            init(packetInfoManager);
+            init(getPacketInfoManager());
         });
     }