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 ('55c6698628d1db44aafe85ad2e3b90eb', -1, 1711699188, 1711699188, '3656b45a', 0, 0, 0)

Line : 187
File : sessions.php