phpBB by Przemo : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('f40faff7e590d5c54fe4c6fcba37f76b', -1, 1539760623, 1539760623, '36c6d41e', 17, 0, 0)

Line : 445
File : sessions.php