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 ('f6f9e259a2fb2dfaa34155f8f5ccb9d2', -1, 1711679918, 1711679918, '12d1d11c', 2, 0, 0)

Line : 187
File : sessions.php