Umlaute missing in Unity GUI.

I read the german text from my Database and there it IS supported. Also when i show the Project in Unity itself it views the correct characters. But when i Build the Project and open the EXE File there are just the question marks. What can i do against it?

As far as I know, question marks turn up when the given font doesn’t support the characters you’re trying to render, so I suppose the solution is to package a working font with your build.