K, I found it
It's in the settings.json file
Line 4
"FileNameTemplate": "{Races}\\{Genders}\\{Ages}\\{HairColors}{SkinColors}{TitSizes}{AssSizes}{PenisSizes}{HairLengths}{HairStyles}{EyeColors}{EyeShapes}{Horns}{Furs}{Heights}{Custom}{CRC}",
The double slashes get loaded directly
Now it converts the '\\' in the .json file into File.separator