phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '0' 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 ('fb4d74d6262024276117a201fe9d382d', -1, 1537833755, 1537833755, '3650537b', 0, 0, 0)

Line : 187
File : sessions.php