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 ('7050f7a9d1e8127d9ee872e2947867aa', -1, 1550867748, 1550867748, '6b17b0a2', 8, 0, 0)

Line : 189
File : sessions.php