Index: /branches/release-34/lib/MT/App/CMS.pm
===================================================================
--- /branches/release-34/lib/MT/App/CMS.pm (revision 1866)
+++ /branches/release-34/lib/MT/App/CMS.pm (revision 1874)
@@ -676,5 +676,5 @@
                 condition => sub {
                     my $app       = MT->app;
-                    my $tmpl_type = $app->param('filter_key');
+                    my $tmpl_type = $app->param('filter_key') || '';
                     return $tmpl_type eq 'system_templates' ? 0
                       : $tmpl_type    eq 'email_templates'  ? 0