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 ('8bb0b7c6ac7bd60e0c02b73d4b7991b1', -1, 1711709865, 1711709865, '2ccac6ad', -4, 0, 0)

Line : 187
File : sessions.php