diff --git a/plugins/org.locationtech.udig.tool.edit/src/org/locationtech/udig/tools/edit/animation/MessageBubble.java b/plugins/org.locationtech.udig.tool.edit/src/org/locationtech/udig/tools/edit/animation/MessageBubble.java
index 85dd1872e3..f5a59ec45f 100644
--- a/plugins/org.locationtech.udig.tool.edit/src/org/locationtech/udig/tools/edit/animation/MessageBubble.java
+++ b/plugins/org.locationtech.udig.tool.edit/src/org/locationtech/udig/tools/edit/animation/MessageBubble.java
@@ -221,8 +221,10 @@ public void setTextColor( Color textColor ) {
     @Override
     public void setValid( boolean valid ) {
         super.setValid(valid);
-        display.removeMouseListener(mouseListener);
-        display.removeMouseWheelListener(wheelListener);
+        if (display != null) {
+            display.removeMouseListener(mouseListener);
+            display.removeMouseWheelListener(wheelListener);
+        }
     }
     
     private MapMouseListener mouseListener=new MapMouseListener(){