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 ('2c9d4f2e726fe62922d109fe6364035d', -1, 1709633806, 1709633806, '2cc84d5c', -4, 0, 0)

Line : 187
File : sessions.php