I am using 3 languages: Ukrainian (default), English and Russian. The plug-in works perfectly, but the name of the month (in the date of comment or post) looks like �������. Everything else (including calendar in the widget) are translated correctly.
I have changed the text encoding in the browser to try to find out if it is the encoding issue and yes - the month's name is in KOI8-U - somehow.
Wordpress 4.9.4
qTranslate: 3.4.6.8