phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_real_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('1d9bf4d59e5ebf58835226a37b0037ef', -1, 1438228825, 1438228825, '369f340a', 3, 0)

Line : 158
File : /var/www/vhosts/pravniki.info/httpdocs/includes/sessions.php