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 ('a5a7d59c783bf55cf7e2f6512eedc851', -1, 1722040254, 1722040254, '0391ab6f', -4, 0, 0)

Line : 172
File : /home/rebkell/public_html/boards/includes/sessions.php