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 ('5039817dc2978a4046e2a0ed452784ca', -1, 1711675777, 1711675777, '23ab16dc', -4, 0, 0)

Line : 187
File : sessions.php