如何解决CI框架的Disallowed Key Characters错误提示

function _clean_input_keys($str)
{
    if ( ! preg_match("/^[a-z0-9:_\/-]+$/i", $str))
    {
        exit('Disallowed Key Characters.');
    }
    // Clean UTF-8 if supported
    if (UTF8_ENABLED === TRUE)
    {
        $str = $this->uni->clean_string($str);
    }
    return $str;
}

function _clean_input_keys($str)  
{  
    $config = &get_config('config');  
    if ( ! preg_match("/^[".$config['permitted_uri_chars']."]+$/i", rawurlencode($str)))  
    {  
        exit('Disallowed Key Characters.');  
    }  

    // Clean UTF-8 if supported
    if (UTF8_ENABLED === TRUE)
    {
        $str = $this->uni->clean_string($str);
    }
    return $str;  
}