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 ('77b8df16d36a956a863c8ce31cfac337', -1, 1540330781, 1540330781, '36e0387e', 3, 0, 0)

Line : 187
File : sessions.php