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 ('db3fb8edd8d500ce8d8cf1084cfc6f00', -1, 1534873846, 1534873846, '36c42a08', 5, 0, 0)

Line : 187
File : sessions.php