Before next "Huge Update"
After the recent "Huge Update" Lots of people did not know what they needed to do by way of clearing cache and/or updating the game and, in consequence, were shut out for various periods with the game refusing to load beyond a certain point.
So my suggestion is that before a maintenance which introduces changes which require the cache to be cleared/updating your notice to players in News, on Facebook and/or here contain an account of what PC, Facebook and mobile phone users should do so that the game can load.