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 ('cddb5554f7c9f5f9ef733b512ed8df5c', -1, 1708588897, 1708588897, '2cc84d5c', -8, 0, 0)

Line : 187
File : sessions.php