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 ('0c95987d57d3733d00d36268f8c32ba0', -1, 1553090875, 1553090875, '36e2af65', -8, 0, 0)

Line : 187
File : sessions.php