usermin 20000 work but virtualmin 10000 not working

hi, i have ubuntu 16.04 x64 vps. i could login to virtualmin weel but yesterday it goes down and it shows time out on 10000 port. i restart webmin : /etc/webmis/restart and its status is ok. /var/webmin/miniserv.error file has no error and ps auw | grep miniserv returns root 14776 0.0 0.0 12948 968 pts/0 S+ 11:18 0:00 grep --color=auto miniserv

i was 1 time nano /etc/shadow and save that , i dont know what is going on.

please help me to access virtualmin