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 ('5a14d251cff9d81dd6aa06c54b8527e1', -1, 1560715372, 1560715372, '36912d8f', -6, 0, 0)

Line : 191
File : sessions.php