Steps to reproduce the issue

Install J4Beta, at the end try to install italian as additional language

Expected result

italian is installed

Actual result

got a warning and language not installed:

System information (as much as possible)

i did try on both linux (virtual host) and XAMPP local host

Additional comments

other languages have no problems (or at least the ones i did try.. like german or french).
All the languages have "versione 3.9.x.y" beside, but just italian does not install... if something is missing in the translation i'm willing to help