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 ('a8d5272202b61ccc4d5c0434b1eef8a5', -1, 1710839224, 1710839224, '03ec1217', 6, 0, 0)

Line : 187
File : sessions.php