PHP Fatal error: Call to a member function item() on a non-object when call $this->config->item('config_item')

[eluser]Unknown[/eluser]
is anyone knows how to fix this kind of problem? or anyone ever been had same stuff?

the error happen on every call of config item rather in libraries classes(eg:form_validation class) or in application controller

if i print_r($this->config) it shows array of config content


any help would be very helpfull for me

thank you