Can't connect to server

crio-user@rj33536:~/workspace/rj33536-ME_QBOX$ ftp 0.0.0.0 8081
Connected to 0.0.0.0.
500 OOPS: vsftpd: cannot locate user specified in ‘ftp_username’:ftp

Make some changes in the config file. Change parameters like anonymous_enable, write_enable, local_enable