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 ('d5b50e6a0d1590e441958eaf44af97de', -1, 1540330817, 1540330817, '36e0387e', 3, 0, 0)

Line : 187
File : sessions.php