Trying to translate RimWorld and found a bug :)
In file MenusMain.xml you cannot change definition of Gameplay:
<LanguageData>
[...]
<Gameplay>Gameplay</Gameplay>
[...]
</LanguageData>
If you change it, game wont generate world. When you click 'Start' dialog box 'Generating box...' shows only for a second and disappears, leaving you on 'Create characters' screen.
Wow, my mistake! I'll fix it.