Name Generator - foreign characters/accents

Have imported custom list into Name Generator - Serbian names related to a current WIP.
The foreign characters/accents appear as underscore _ when generated. For example letters such as ć, č, ś, š.
Seems this is an issue specific to Name Generator as have had no problems in document using same characters. Also will be using German names and noticed that the existing German forename file includes umlaut with no problems.
Suggestions/help will be greatly appreciated.
Thank you.

Emailed tech support and problem solved - Thanks to Astrid.
The files were corrupt, maybe my ancient copy of Excel was to blame. Recreated them as comma separated in Text Edit and voila! All working fine now.