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 ('106332f76416e6a84b29a8a8b5dc1330', -1, 1539591906, 1539591906, '369c27f5', 4, 0, 0)

Line : 187
File : sessions.php