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 ('576be7f7b7d131b290f4e8fb73b8b768', -1, 1711707507, 1711707507, '36c692e0', -10, 0, 0)

Line : 187
File : sessions.php