Fix bug.

app/controllers/announcements_controller.rb

@@ -71,7 +71,7 @@ class AnnouncementsController < ApplicationController
     if (params['category'] != page.categories rescue true)
       @annc_page_title = Category.find(Array(params['category']).first).title rescue nil
     end
-    if (params["tags"] != page.tags && params["tags"].count == 1 rescue true)
+    if (params["tags"] != page.tags && !params["tags"].blank? && params["tags"].count == 1 rescue true)
       @annc_page_title = Tag.find(Array(params['tags']).first).name rescue nil
     end
     {