I noticed that UtilExtension localization files (.wxl) are missing for zh-CN, ru-ru, fr-fr locales in the latest wix sources.
Only en-us, de-de, ja-jp are present.
The installer that I am developing supports zh-CN, ru-ru, fr-fr, en-us, de-de, ja-jp locale.
Can anyone please tell me how to get these?
This will wait until someone wishes to contribute. For now you can make e.g. en-US the default culture, and those phrases which are not translated will be displayed in English. Not perfect, but that's the best option, imho.
Alternatively, you can contribute yourself and fix this issue for you and others who face this in future. :)