phpBB by Przemo : 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 ('8fa6157753fb9c03c1cdafa9418f9008', -1, 1539729243, 1539729243, '36c60f14', -4, 0, 0)

Line : 445
File : sessions.php