Hi guys,
I purchased the Witcher 3 1 month ago and have not touched it till now. The problem is when I load in Kaer Morhen almost all of the textures are missing, no walls no character model just floating trees. I'm on PC and I'm using a ASUS R9 280 Series.
See attached picture.

That is almost certainly a fault in your download.

Delete and reinstall.

If you still have problems, can you post some details of your rig? CPU? Video Card, ect.