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 ('f3167af2fd6644b88951257b0a57d0bd', -1, 1539612062, 1539612062, '36c637a7', -11, 0, 0)

Line : 187
File : sessions.php