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 ('38a6cb7e19121672e067f64ba3a7b99c', -1, 1558648852, 1558648852, '3417ea07', -9, 0, 0)

Line : 187
File : sessions.php