So all you're seeing is the Watermill terrain (with hills and water) but just no objects? This can be fixed without re-installing, I've done it before.
Go to your Feralheart >> Media >> Terrains >> Watermill folder and open up the WaterMillObjects.cfg file with a program such as Notepad. It should be empty, yes?
Copy all the text
here and paste it into the empty .cfg file you have opened. Then click
File >> Save.
Open up Feralheart and
hopefully everything should be back in order