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 ('59c2b7725567645569ed15b87a45fd27', -1, 1539685414, 1539685414, '369ed0bd', 0, 0, 0)

Line : 187
File : sessions.php