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 ('9ea5d654b781f0b8948c2d5e4bdff7dc', -1, 1542518976, 1542518976, '36a31439', 0, 0, 0)

Line : 193
File : sessions.php