Thank you, it's fixed now. I can enjoy Terragen finally.
Btw, there is a problem with the additionnals downloads (3D Models and video tutorials). When I click on the download links nothing happen. Right clicking doesn't work either. I disabled AdBlock just in case there was a conflict but it doesn't work either. I'm on Chrome on Windows if it help.
EDIT: I installed Firefox and tested and it worked. I was able to download the add-ons. So the problem is with Chrome.