unable to login to web interface centos 7.4.1708

[mandeep242]

I have installed vestacp on centos 7.4, but I am unable to login to web panel. I have tried using root and admin user.
but it always saying invalid username or password

also the commands
/usr/local/vesta/bin/v-change-user-password admin MyPassword

/usr/local/vesta/bin/v-check-user-password admin Mypassword

giving me passwordmissmatch error, I have enough space on server.