asp.net mvc 4 - Error page not being used on exception -

asp.net mvc 4 - Error page not being used on exception -

when exception thrown on mvc4 (.net) application, error page shown.

my web.config file has

<system.web> <customerrors mode="on" defaultredirect="~/error/" /> <compilation debug="true" targetframework="4.5" /> </system.web>

but, in controller page, diving 0 (to test it). naturally, exception thrown not redirect me error controller. instead, page shows:

sorry, error occurred while processing request.

my errorcontroller is:

public actionresult index() { homecoming view(); }

and routes are

public static void registerroutes(routecollection routes) { routes.ignoreroute("{resource}.axd/{*pathinfo}"); routes.maproute( name: "default", url: "{controller}/{action}/{id}", defaults: new { controller = "home", action = "index", id = urlparameter.optional } ); }

and view empty:

@{ viewbag.title = "there fault."; }

a online shows web.config, mine appear correct.

i understand message if error controller or error view had faults!

please note, have used customerrors mvc many times before, on same server, i'm lost why occurring.

what should doing?

asp.net-mvc-4