When further away some textures seem to come back…
Interesting. I wonder what caused your texture assets to get corrupted or deleted.
I reinstalled the official folder now by deleting it and letting the sim redownload everything again. Took over the official folder from my previous windows installation, this worked before but this time it seems some files might have gotten corrupted.
Now it’s working again 
The same happens to me at LSZR (Altenrhein, Switzerland), purple everywhere. This is an Asobo handcrafted airport from one of the World Updates. I removed ALL add-ons (via add-on linker) and the problem persists. Also deleted the user and content xml files, to no avail. Any ideas what else could be done? This is my home airport and everything purple is an immersion killer…