ssh登录主机执行下
vim /etc/pam.d/gdm-autologin

注释行 "auth requied pam_succeed_if.so user != root quiet success"

vim  /etc/pam.d/gdm-password

注释行 "auth requied pam_succeed_if.so user != root quiet success"

Ubuntu图形界面root登录出现“sorry, that didn't work please try again”