phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('679eb9415ae0b3a9a30e3183cd9b5bad', -1, 1560717979, 1560717979, '03550a3e', 31, 0, 0)

Line : 191
File : sessions.php