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 ('b7d0456d52b7b9d25b05fe424be8d586', -1, 1558393051, 1558393051, '36a3147b', 7, 0, 0)

Line : 187
File : sessions.php