German characters (with Umlaut) are shown as Cyrillic charters

[blackdog]

I have written a Qt5 QML App but still have a problem, German characters (with Umlaut) are shown as Cyrillic charters.
ä → д
ö → ц
ü → ъ
I was hoping the translation file would solve the problem but no, translation works fine but characters are still wrong :(
In Qt Example Apps these charters work fine so I guess its no related to my development environment.
Any idea how I can fix this problem?

[anda_skoa]

Is the text itself correct? I.e. if you log it or write it into a file?

Is the font capable of displaying these characters?

Cheers,
_

[blackdog]

Found the Problem :)
You were right, the font was not capable of displaying these characters.
Thx for you help.