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 ('f81cd646d1ce4d1e4e77ca85f60d38fb', -1, 1711702611, 1711702611, '2cd35b17', 2, 0, 0)

Line : 187
File : sessions.php