diff --git a/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPreferencePage.java b/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPreferencePage.java
index 2f1da24..5f9683f 100644
--- a/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPreferencePage.java
+++ b/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPreferencePage.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2001, 2009 IBM Corporation and others.
+ * Copyright (c) 2001, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -508,6 +508,9 @@
 			IStructuredSelection selection = (IStructuredSelection) _validatorList.getSelection();
 			ValidatorMutable val = (ValidatorMutable) selection.getFirstElement();
 
+			// In Mac OS, val can be null (see bugs 397349 and 412826)
+			if (val == null) return;
+			
 			switch (columnToEdit) {
 			case 1:
 				_changeCount++;
diff --git a/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPropertyPage.java b/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPropertyPage.java
index 53c574a..87efe72 100644
--- a/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPropertyPage.java
+++ b/plugins/org.eclipse.wst.validation.ui/vf2/org/eclipse/wst/validation/ui/internal/preferences/ValidationPropertyPage.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2001, 2009 IBM Corporation and others.
+ * Copyright (c) 2001, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -568,6 +568,9 @@
 		protected void columnClicked(int columnToEdit) {
 			IStructuredSelection selection = (IStructuredSelection) _validatorList.getSelection();
 			ValidatorMutable val = (ValidatorMutable) selection.getFirstElement();
+			
+			// In Mac OS, val can be null (see bugs 397349 and 412826)
+			if (val == null) return;
 
 			switch (columnToEdit) {
 			case 1: