Xftp failed to connect with root user

Xftp connection using linux upload files, you can use an ordinary user connections, you can not use root connection
to modify / etc / ssh / sshd_config file, there is no need to use the root user privileges to other users
add

# Authentication:
LoginGraceTime 120
PermitRootLogin without passwd
StrictModes yes

Finally restart, you can connect to the root user