phpBB : 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 ('4c54b8783f16859bacb2b758150b6fac', -1, 1544905152, 1544905152, '22e42942', 0, 0, 0)

Line : 193
File : sessions.php