java - Charset in JTextPane which using AdvancedRTFEditorKit -

i'm having problems charset encodings. i'm using advancedrtfeditorkit (free closed source library: http://java-sl.com/advanced_rtf_editor_kit.html).

if copy special characters (ěščřžýáíé) ms word , paste them sample delivered advancedrtfeditorkit library, works fine. if same simple sscce uses advancedrtfeditorkit, appear rectangles. know i'm doing wrong?

this problem occurs ms office products. libreoffice works fine.

my sscce:

public static void main(string[] args) {     jframe frame = new jframe();     frame.setsize(350, 300);     frame.setdefaultcloseoperation(jframe.exit_on_close);      jtextpane pane = new jtextpane();     pane.seteditorkit(new advancedrtfeditorkit());      frame.add(pane);     frame.setvisible(true); } 

after many changes in code figured out there isn't problem app. problem running app directly netbeans ide. don't know why, ide somehow encode/decode interaction os.