Unable to upload contacts with Cyrillic font

When uploading a csv with Cyrillic font, the text just turns all into question marks (like ?????). Is there something that I need to add or enable on our site? The export to Cyrillic font (for Russian, etc.) works just fine after I added wkhtmltopdf a few weeks back based upon your suggestion, but for some reason importing contacts with this type of text does not work.

Please advise on what I can do to fix this problem as it is a major issue for our sites. I've looked through the forums, etc, but apologies if I missed any previously documented fixes.

Thanks,
Evan