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 ('863bf97d0ae1cad7d253a35dc995fe44', -1, 1711706999, 1711706999, '2cc1d069', -7, 0, 0)

Line : 187
File : sessions.php