phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('e26a11a9f5ff17ac842226e872f1493b', -1, 1495661302, 1495661302, '369205c4', 5, 0, 0)

Line : 172
File : sessions.php