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 ('6aec73be8706a3f37d46ddd94d6d2795', -1, 1711617503, 1711617503, '03e792ac', -11, 0, 0)

Line : 187
File : sessions.php