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 ('647855c4ed766af84d24eef52e8d55cf', -1, 1708694762, 1708694762, '03ecdf6a', -7, 0, 0)

Line : 187
File : sessions.php