Hi Christian,
Sorry for delay in responding you.
By default, EditControl uses ASCII Encoding. If you want to use Unicode characters especially some special characters in each language, then you need to call the SetEncoding(Encoding) method to change the Encoding to UTF8 or Unicode. The following code snippet illustrates this.
this.editControl1.SetEncoding(Encoding.UTF8);
Please let me know if any queries regarding.
Regards,
Fathima.