diff --git a/mozilla/xpfe/global/resources/locale/en-US/about.html b/mozilla/xpfe/global/resources/locale/en-US/about.html
index 1680761c2f4..75ba63baa39 100644
--- a/mozilla/xpfe/global/resources/locale/en-US/about.html
+++ b/mozilla/xpfe/global/resources/locale/en-US/about.html
@@ -71,8 +71,12 @@ h1 {
 <a id="mozlink" href="http://www.mozilla.org/releases/">Mozilla </a>
 </h1>
 <script type="application/x-javascript">
-  document.getElementById("mozlink").firstChild.appendData(navigator.userAgent.match(/rv:([^;)]+)/)[1]);
-  document.getElementById("mozver").appendChild(document.createTextNode(navigator.userAgent));
+  // using try..catch to handle empty useragents and other cases where the regex fails to apply
+  try {
+    document.getElementById("mozver").appendChild(document.createTextNode(navigator.userAgent));
+    document.getElementById("mozlink").firstChild.appendData(navigator.userAgent.match(/rv:([^;)]+)/)[1]);
+  }
+  catch (e) {}
 </script>
 </td>
 
diff --git a/mozilla/xpfe/global/resources/locale/en-US/about.xhtml b/mozilla/xpfe/global/resources/locale/en-US/about.xhtml
index 1680761c2f4..75ba63baa39 100644
--- a/mozilla/xpfe/global/resources/locale/en-US/about.xhtml
+++ b/mozilla/xpfe/global/resources/locale/en-US/about.xhtml
@@ -71,8 +71,12 @@ h1 {
 <a id="mozlink" href="http://www.mozilla.org/releases/">Mozilla </a>
 </h1>
 <script type="application/x-javascript">
-  document.getElementById("mozlink").firstChild.appendData(navigator.userAgent.match(/rv:([^;)]+)/)[1]);
-  document.getElementById("mozver").appendChild(document.createTextNode(navigator.userAgent));
+  // using try..catch to handle empty useragents and other cases where the regex fails to apply
+  try {
+    document.getElementById("mozver").appendChild(document.createTextNode(navigator.userAgent));
+    document.getElementById("mozlink").firstChild.appendData(navigator.userAgent.match(/rv:([^;)]+)/)[1]);
+  }
+  catch (e) {}
 </script>
 </td>