Special characters, pdf invoice

-- url of the page with the problem -- : www.coloidale.ro
-- HikaShop version -- : 2.4.0
-- Joomla version -- : last
-- PHP version -- : 5.5.41
-- Browser(s) name and version -- : all
-- Error-message(debug-mod must be tuned on) -- : not applicable

When sending the pdf invoice, the special character like ăîâşţ, for Romanian language, are replaced with a ? mark.

Now, we tried to follow zour advice in a previous post:

"Thanks to try to edit the files "plugins\hikashop\attachinvoice\attachinvoice.php" and "plugins\hikashop\attachinvoice\attachinvoice\invoice.php" with notepad++ and change the encodage by clicking on "encodage" and select "UTF-8 (without BOM)".

There was maybe an encodage issue after the last edition of that file."

We opened in Notepad each of those two files, and saved them in UTF-8, not ANSI.

Still, the behaviour is the same. We tried to select some other font in the plugin itself, but still no effect.

Please help us to solve this disturbing problem.

Indeed, it is the product name, and yes. It may come from the Falang translation, and this happens only in the pdf file.