phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO forum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('decfe16628bf2c178ba417d00a451623', -1, 1539807543, 1539807543, '36a2766b', -9, 0, 0)

Line : 187
File : sessions.php