phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO iabb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('b7c23b4dbce7623b09e14a76eb0277a0', -1, 1561033104, 1561033104, '0358dc5d', 31, 0, 0)

Line : 187
File : sessions.php