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 ('c8ae978a4854ef2bfd0b9cd88e279452', -1, 1556279655, 1556279655, '365b79ff', -2, 0, 0)

Line : 187
File : sessions.php