How to reproduce:
- Consider C1 site with multiple languages( e.g. English and Danish)
One of the languages(usually default language) can have empty "URL mapping name" property (for example, English).
Danish language has "URL mapping name" = de
So C1 URLs e.g. to the home page will be like this:
NiceURLs will not work correctly for English language. (but if English language also has "URL mapping name" , e.g 'en', then it works as expected)