Can't access 2nd sites' dashboard after creating /w "add site"

Hi,

I created a 2nd site with my multisite install and I can’t access the dashboard.
This is the error: The page isn’t redirecting properly. Firefox has detected that the server is redirecting the request for this address in a way that will never complete.
This is the site: https://www.casinofun.lv/ru/

I’ve cleared cache, deleted cookies, deleted the only plugin I had –
Multisite Language Switcher and disabled my theme and enabled default one. Still doesn’t help.

In my ftp client I don’t see a “/ru” folder if that means something.

Thank you in advance!

Regards,
Roman