CKFinder standalone .popup() setting language does not work

Question

Good day.

I usually opened CKFinder standalone as following:

function browseServer(inputId) {
    var finder = new CKFinder( );
    finder.BasePath = '/ckfinder/' ;
    finder.SelectFunction = setFileField ;
    finder.SelectFunctionData = inputId ;
    finder.Popup() ;
}

I want to open this with a new language (based on user language), but even hard coded passed language setting does not work. Its opening every time in german actually.

I googled and watched into the ckfinder documentations, dont figured out how to let it work.

I tried:

Delete all cache and cookies

 // var finder = new CKFinder( );
 finder = new CKFinder( );

Delete all cache and cookies

Then between the instanciation and .Popup() i tried all constellations of ..

//  finder.defaultLanguage = 'it';
//  finder.language = 'it';
finder.langCode = 'it';

.. with every time deleting all cache and cookies. And all this with and without 'var' before the var declaration and instanciation of 'new CKFinder()'.

What i am doing wrong? Tested in FF and Chrome.

Thaks all in advance.

EDIT:

I also tried to pass those lang config possibilities as object into new CKFinder({});