PHP 7 user sessions issue - Failed to initialize storage module

function _open should return true to avoid this error.

It can not be null or empty whatever we use either database or file.

When we use database to store session data, we keep it blank or no Boolean return. that is the main reason for this error.

class session_handler{
    public function __construct()
    {
        session_set_save_handler(
            array($this, "_open"),
            array($this, "_close"),
            array($this, "_read"),
            array($this, "_write"),
            array($this, "_destroy"),
            array($this, "_gc")
        );
    }

    public function _open($savePath, $sessionId)
    {
        return true;
    }

    public function _close() {  }    
    public function _read($id) {  }
    public function _write($id, $data) {  }
    public function _destroy($id) {  }
    public function _gc($max) {  }}

It is only for PHP 7. I do not know it is a bug or not.

https://stackoverflow.com/questions/34125849/php-7-user-sessions-issue-failed-to-initialize-storage-module