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 ('6bfd99407ec9bd997d74a2d42ecb6bc0', -1, 1540157127, 1540157127, '36a174e1', -4, 0, 0)

Line : 193
File : sessions.php