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 ('34a2641e1bc34c93d520fa2fdc5f0e8a', -1, 1537467476, 1537467476, '36a2efe9', 0, 0, 0)

Line : 189
File : sessions.php