Hi, what type of login page do you use?
Are you using the login.html (default) or do you have a custom login page configured as a page in your model?
The login page of Mendix will automatically be shown in the language of the internet browser.
This will work however only on the language you have activated in your app.
You can verify it by changing the language in your own browser.
In firefox, you go to Settings and search for ‘Language’.
Then you can set the prefered language for displaying websites.
In other browsers this probably will be comparable.
If this is not working and your login page is not showing in Russian, switch to a custom login page.