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 ('372bf560357d68bc89f393251d41b3b6', -1, 1548239665, 1548239665, '36535d55', -4, 0, 0)

Line : 187
File : sessions.php