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 ('75b99e669b6e20bb2fb101c0cdf85b38', -1, 1728099935, 1728099935, '2cdcfbec', -1, 0, 0)

Line : 172
File : sessions.php