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 ('21a38dc36b9a760b84dfa9d9037768bd', -1, 1708692808, 1708692808, '03ecdf6a', -4, 0, 0)

Line : 187
File : sessions.php