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 ('ad05a75fe7122c4ea50a9bdaabf3bafa', -1, 1711613507, 1711613507, '23ab9f8d', -4, 0, 0)

Line : 187
File : sessions.php