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 ('85f7bfe0e4e020e04e11364f0b79a052', -1, 1709137880, 1709137880, '03ef4c19', -4, 0, 0)

Line : 187
File : sessions.php