phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('953f1bea75c8b2765d98bd074d6f0c1b', -1, 1550867463, 1550867463, '6b17b0a2', 18, 0, 0)

Line : 189
File : sessions.php