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 ('ac9dad8fcb72c1808755d1082d3d0b58', -1, 1539985408, 1539985408, '3650bc57', -10, 0, 0)

Line : 445
File : sessions.php