I tried to translate into Italian the sentence related to the 404 not found page.
I replaced "Oops, you've encountered an error" with "Oops, si è verificato un errore", but the accented letter "è" does not display correctly. I tried with è too but nothing. You can check that by visiting a wrong url on my website.
I used the string TPL_GK_LANG_ERROR_INFO on the language manager.
My website is www.casino-online.bz username gavick and password gavick. Template override is enabled.