Cannot save a PDF with a new font

Lately, I got a document to translate into Russian. As usual, I ran it through Infix (v. 4.25 Pro) and started to edit after downloading a font that was required for my needs (Freesans). I reached page 3 of the document to find that it wouldn’t save. Attached below is a screenshot of an error I have never experienced using Infix. I am at a complete loss.
http://i97.fastpic.ru/big/2017/1112/2b/bd50b300e27a3e6b62e5a0c75bbe932b.jpg

Can you please try using “Save As” and selecting a different path to save to. Does that work?

Thanks, Simon.

Nope, it doesn’t. I have no idea why Infix keeps asking me that question. Neither do I understand why the name of the document looks corrupted after I installed the font required for my translation.