diff --git a/Runtime/engine/UIWidgetsPanel.cs b/Runtime/engine/UIWidgetsPanel.cs
index c886fea3..440c460f 100644
--- a/Runtime/engine/UIWidgetsPanel.cs
+++ b/Runtime/engine/UIWidgetsPanel.cs
@@ -192,6 +192,13 @@ public WindowPadding viewInsets {
         }
 
         protected override void OnDisable() {
+            
+            if (this._viewMetricsCallbackRegistered) {
+                this._viewMetricsCallbackRegistered = false;
+                UIWidgetsMessageManager.instance?.RemoveChannelMessageDelegate("ViewportMatricsChanged",
+                    this._handleViewMetricsChanged);
+            }
+            
             D.assert(this._windowAdapter != null);
             this._windowAdapter.OnDisable();
             this._windowAdapter = null;
@@ -417,4 +424,4 @@ public Window window {
             get { return this._windowAdapter; }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/package.json b/package.json
index 5fd9bb09..1d741393 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
 	"name": "com.unity.uiwidgets",
 	"displayName":"UIWidgets",
-	"version": "1.5.4-preview.1",
+	"version": "1.5.4-preview.2",
 	"unity": "2018.4",
 	"description": "UIWidgets allows you to build beautiful cross-platform apps through Unity",
 	"dependencies": {