Moving WP to a different server

Yesterday I migrate my website from Bluehost VPS to WP Opt Business Plan. Now my registered users cannot login.

Some of them say that they cannot have acess to /wp-login.php Others are saying that their credentials are not being accepted.

I am trying to access http://www.tribcast.com.br/wp-login.php with no success.

I used backupbuddy on the migration process, and there was an alert saying that bluehost .htaccess file would be substitute by backupbuddy's. (I don't know if that is the reason)

Please, any help would be much appreciated.