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 ('207355cf3fe291b58945eb2a41b67cdc', -1, 1708884417, 1708884417, '03eb916c', -4, 0, 0)

Line : 187
File : sessions.php