Session: Error while trying to free lock for ci_session

Thanks spjonez,

but I don get it, where to call session_write_close() ?
For example I am having this in MY_Controller in __construct:

PHP Code:

if(isset($this->session->userdata["user_id"])){
    $data["userdata"] = $this->session->userdata;
        if ($this->config->item($this->uri->segment(1), "lang_list") !== NULL){
            $this->current_lang = $this->uri->segment(1);
        }
    else{
        $this->current_lang = $this->session->userdata["lang"];
    }
} 


Also I am having some other checks in session or update session variable like this:

PHP Code:

if (isset($this->session->userdata["notifications"]["budget"])) {
    $notifacations = $this->session->userdata["notifications"];
    $notifacations["budget"] = true;
    $this->session->set_userdata("notifications", $notifacations);
} 


Where I should put session_write_close() ?
Also my app is heavily depends on AJAX calls.
I tried in __desctruct function of MY_Controller to add session_write_close() but with no success.
Beside this I have on numerous places in app where I do echo like this:
 

PHP Code:

<?php echo $this->session->userdata["lang"];?>

Should I after every operations with sessions to call session_write_close() function?