Since the latest 3.2.6 update, a few players have reported that some of the text in-game is missing in Russian.

Our team has identified the problem and is working on a fix for the next update of the game.

Meanwhile, a simple workaround seems to resolve the issue by changing the font of the text in-game.

To do so, please go to "Options" (second spot from the top) then "Video" (again, second spot from the top). The current font should be visible, you can change it with the left and right arrows. 

The following video will show you the path to follow: