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 ('d11472ad42e76f377e0afb96e0bf06bc', -1, 1561600796, 1561600796, '36e21eba', -4, 0, 0)

Line : 191
File : sessions.php