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 ('9a77c056407b9606a12611c4e4c08c63', -1, 1711614962, 1711614962, '03e3ef09', -4, 0, 0)

Line : 187
File : sessions.php