From 43a954f4a02e16c763d2e399c0511e2ed7927239 Mon Sep 17 00:00:00 2001
From: Nathanael Anderson <nathan@master-technology.com>
Date: Mon, 24 Aug 2015 02:08:09 -0500
Subject: [PATCH] Added a safe guard in case somehow the createPage does not
 return a valid page component.

---
 ui/frame/frame-common.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ui/frame/frame-common.ts b/ui/frame/frame-common.ts
index 822c8bf7d..cfc4e6295 100644
--- a/ui/frame/frame-common.ts
+++ b/ui/frame/frame-common.ts
@@ -58,7 +58,7 @@ export function resolvePageFromEntry(entry: definition.NavigationEntry): pages.P
             trace.write("Calling createPage()", trace.categories.Navigation);
             page = moduleExports.createPage();
             var cssFileName = fileResolverModule.resolveFileName(moduleNamePath, "css");
-            if (cssFileName) {
+            if (cssFileName && page && page.addCssFile) {
                 page.addCssFile(cssFileName);
             }
         }