open sans

I’ve fixed it by myself:)
in functions.php I’ve changed
https://fonts.googleapis.com/css?family=Open+Sans
to
https://fonts.googleapis.com/css?family=Open+Sans&subset=latin,latin-ext

and in style.css
font-family: “open sans”
to
font-family: “Open Sans”

thx

Be careful with WordPress 3.8. The admin theme has their own implementation of Open Sans. They have a few workarounds for other alphabets, but it’s best to be aware that it may be an issue.

Read on:
https://www.webdevelopmentgroup.com/2014/01/replace-open-sans-in-wordpress-3-8/